Level Transfusion to level 5, as it is Vladimir's most constant single target damage ability, as well as his heal. Remember that the base healing component is a flat amount modified by additional ability power, so even if the target is not damaged (i.e. shielded, blocked by Banshee's Veil, or blocked by Kayle'sIntervention), you will still be healed by the ability.
Having at least 1 rank of Sanguine Pool can help you survive for much longer, as it resets aggro. A skilled player can use it to turret dive or to dodge abilities. However, it has a long cooldown and a short duration, so do not become too reliant on it for escapes.
It is wise to use Sanguine Pool to chase down an enemy or escaping from one. Using it as a damage skill could leave you extremely vulnerable if you can't kill the enemy.
Tides of Blood can be cast without having any enemy targets nearby. This can allow you to keep the buff constantly active or build stacks to prepare for an attack. It can also increase the effectiveness of a Health Potion if used prior to activating it. Additionally, using it when a stealthed enemy is nearby will allow you to detect them, they will not destealth, but you will be able to see the missiles flying into their direction. This also works if an enemy is concealed in brush nearby.
Gaining stacks of Tides of Blood prior to a gank can result in devastatingly high nuking ability upon multiple enemies. For the same reason, Vladimir's damage output rises dramatically after about 10 seconds during team fights as his stacks increase very quickly, which can result in massive AoE damage when combined with Hemoplague.
Hemoplague causes targets to take bonus damage, so it is advised to use it at the beginning of team fights to increase the overall damage your team can inflict upon your enemies. Mid to late game, Banshee's Veil will negate both the increased damage debuff and the 5 second delayed damage component, make sure to spend as many of the opposing team's charges prior to activating.
Hemoplague can be used to finish off a target low on health. The range to the edge of the AoE is deceptively long; keep this in mind when deciding whether to pursue a target near death.
When using Hemoplague, be wary of champions who can counter the delayed damage, such as those with shields or heals. Do not depend on it to ensure your kill.
Casting Hemoplague will not deal any immediate damage, and therefore can be used to kill low health enemies under their turret.
Spellvamp will heal as soon as spell damage is inflicted on a target, so his Transfusion will have a two part heal, one on damage and one as the particle reaches him. This healing goes for all of his spells as they deal damage. An unexpected heal may occur when his ultimate Hemoplague pops it's damage a small heal will affect Vladimir since AOE spells heal for a percentage less.
Vladimir's Passive, Crimson Pact, allows him to be deceptively tanky while dealing high damage. By building large amounts of AP, Vladimir can bypass Health and focus on damage and durability.
Since Crimson Pact provides bonus Health and AP, items like Abyssal Scepter and Rylai's Crystal Scepter provide both massive defensive bonuses and amazing offensive power on Vladimir. Together they provide 638 HP, 180 AP, 45 MR, slow components, and magic resistance reduction aura that benefits the team.
Void Staff can be used instead of Abyssal Scepter when focusing on killing a target quickly and magic resistance is not necessary.
It's generally advised to get Ionian Boots of Lucidity because Vladimir greatly benefits from CDR and has very limited options of CDR items as a manaless AP caster.
Rabadon's Deathcap is one of the most popular items on Mages. However, because of Vladimir'sCrimson Pact, it also grants 210 health and the 30% bonus AP gained interacts with his passive, making it even more cost effective and powerful.
Deathfire Grasp can make Vladimir a very powerful assassin in combination with Hemoplague. Since the debuffs stack additively, the afflicted enemy will receive 32% increased magic damage. It is suggested, however, to wait at least 1 second after applying Hemoplague because the magic damage delay lasts 5 seconds, whereas Deathfire Grasp's debuff only lasts 4 seconds.
Spirit Visage is an extremely powerful item on Vlad, increasing all of the aforementioned healing by 20%, giving him 10 AP due to his passive and giving much needed 10% CDR.
While in Sanguine Pool Vladimir is not affected by any auras, including auras from items. While no ally or enemy aura will affect him, Vladimir can still take damage from DoT spells like Fiddlesticks'sDrain and Swain'sTorment, and due to the heavy cost of Sanguine Pool, using it to "escape" such spells can actually harm badly.
Rylai's Crystal Scepter is a great item for most casters, but Vladimir will benefit even more from it due to his lack of CC and range as well as his passive: it will grant 540 health / 110 AP beyond the base 400 health / 100 AP. Additionally, the passive gives his spells constant slows.
Guardian Angel is a good potential 5th or 6th item on a tanky build, as you will generally have a lot of health but lack resistances, and its passive will be affected by your Tides of Blood stacks. With full stacks at max rank, you will gain 39.6% of your maximum health upon reviving instead of 30% (or 47.5% with full stacks plus Spirit Visage).
A powerful defensive item is Zhonya's Hourglass, as it provides 168 bonus HP along with the 120 AP and 50 armor.
Early game, stay just out of range of his Transfusion. If he uses it on a minion run forward to harass before his Transfusion cools down.
Vladimir lacks any hard crowd control to interrupt channeled abilities, but watch out as his Sanguine Pool allows him to avoid abilities that have effects while channeling (like Death Lotus) or he can time it to avoid channels that have an effect at the end (like Absolute Zero)
Vladimir is one of the most powerful champions at late game, as he becomes virtually unkillable, with overwhelming damage and can wreck past an AP mage's normal counters, fighters, if he is able to reach this point defeating him proves extremely difficult.
However his late game dominance has a cost, an awful laning phase, with Transfusion having a long cooldown, low damage and healing until rank 3-4, step in to harass right after he uses the skill to farm, his only counter-harass will be Tides of Blood which doesn't deal much damage if not stacked and damages him
Vladimir lane weakness declines by the time he gets his Hextech Revolver as he will be able to heal every attack launched against him, if he is not able to farm properly this item will become delayed and he will remain weak for teamfights
Focusing Vladimir in a teamfight is not a very good idea - he is very tanky due to his passive, he can restore his health quickly and lose all focus with Sanguine Pool.
Trying to kill him takes a long time if he is properly positioned and can distract your team from other key enemy targets such as the ADC and assassins.
If you fail to kill Vladimir late game and he escapes he will be able to fully restore his health with minions and jungle monsters without going to back to base.
Do not underestimate Tides of Blood late game, especially if fully stacked. Average late game Vladimir can dish out from 450 - 540 damage, pre mitigation, from Tides of Blood to all surrounding enemies. With some cool down reduction, he can spam this spell continuously and easily wreak havoc if left unchecked.
Try to harass Vladimir into using his Sanguine Pool early in a fight so he takes more damage from it and cannot use it to escape focus fire. Vladimir will use 20% of his current health whenever he uses Sanguine Pool, so if you force him to use it, you've effectively won the trade.
Remember that Transfusion doesn't heal Vlad until the particle returns to him, and because the animation is two-staged (impalement, then return), most single-target projectiles like Two-Shiv Poison, Vorpal Blade, and Null Sphere will generally hit him before he's healed. This is useful to remember should you be uncertain about last-hitting him.
You can use Quicksilver Sash to remove Hemoplague (which is usually paired with Ignite) if he uses it on you. So buying it against Vladimir is a good and rather cheap counter.
Due to his passive, he gains health as his spells grow more powerful, however this leaves him vulnerable to health percentage damage items and abilities (e.g. Null Zone and Blade of the Ruined King).