First things first: In 1v1:
You can't stun with E.
You can't land W.

You have to rely on your Q which you spam to ap stack(so you don't harass) and your R(which is unavailable pre 6). What do you do? Do you use Q to harass and don't stack it? Then veigar isn't veigar anymore! Do you get ad and auto attack? Not worth the abuse.

Think of singed. He gets destroyed but keeps farming. If you leave solo lane alone he farms infinite creeps in no time. If you kill him it will take too much time and he will rush lane anyway. Veigar is the new singed of mid lane.

With this build you will get pushed out of lane get beat but keep farming those stacks. You will scale so well late game and win many many matches.

It still works!

With new Q range upgrade and W's huge range veigar can get 4 stacks from front and back line creeps.

The tactic is simple: You cast W as enemy creeps march and take position and cast Q when they arrive. You then auto the last front line creeps. And repeat for back line creeps. You farm from a safe distance.

Many veigars rush luden. First things first: You won't enjoy your first 15 mins with this build. This is a farm focused build. You won't help bot. You won't have good presence in 2 drake fights. You just farm without feeding under your tower(use tp to go back to lane).

Luden / Lichbane
High early damage + Low early damage -
High cd - Very Low cd +
Stop spells to cast on enemy - You spam to farm Q then auto +
Weak late game damage - Very High late game damage +

Get lichbane nuff said. You are a ghost early game. You don't need luden. You need to slave those farms.

CONFESSION: 15 min farm you will get insulted and game will be boring
TRUTH: You will win much more with this tactic.

Veigar is not banned. EVER.
Veigar is not picked. EVER.
You can compensate for getting no blue buff with tp long lasting blue potions and passive
You ask for no ganks. Jungler ganks other lanes more.
You don't get ganked. You lose some farm. Camping you is idle because you are playing too passive.
Although this means enemy mid can gank bot In most cases people will rage to kill you going out of their way early. Wasting their precious time.
Your early game items are uber cheap.
Your ultimate will work better against the well farmed ap mid enemy.