Strengths:

One of the best tank shredding adcs in the game.

Can pull off some really fancy outplayes if you do well.

Has really good 1v1 potential and 1v5 potential. (Don't do it unless your Gosu)

Has self defense tools.

First item lifesteal is really nice to have.

Can bring back lost games because of her insane late game scaling.

People don't know how strong vayne can get with her power spikes.

Weaknesses:

Weak laning phase especially vs longer ranged champions and point and click cc.

Weak early in the game.

Short range.

Has a really high skill cap and requires practice to do consistently well.

Does not teamfight that well vs engage type team comps.

The first thing I should mention is never get armor pen, it will actually end up reducing your damage. Instead of an armor pen item you should get an attack speed item. Let me explain why:

Guinsoo's passive builds up after 6 auto attacks in a short period of time. You can see these stacks on the top left of your ability bar. once you reach 6 stacks every other auto attack will trigger on hit effects an additional time including Vaynes Silver Bolts which deal true damage that scales with the enemies health! With all this information you can see how attack speed works well vs tanks for this build.

Infinity edge vs squishies has the same concept of buying effective items. you don't need all of that attack speed when IE lets you 1 shot squishies. Since silver bolts scales off of hp it will do less damage than an IE would to squishies.

Vayne has a weak laning phase especially before she gets her BOTRK. Be careful in lane and try to trade using your silver bolts.

Vayne has a nice power spike after she gets completes the core items (guinsoo's, BOTRK, Berserker's Greaves). This is sometimes enough to come back from a really bad laning phase.
The power spike increases your damage by a lot, you may even be able to fight people that you could not fight 1v1 before (I don't recommend going out of your way to try).

You don't need to do anything special to make this build work. How good this build works is determined by how well you play. I will still cover some basic tips for this build anyway.

Do not try diving the enemy team unless it is a total act of desperation to kill an ultra fed enemy champion. In team fights you mostly want to let your tanks engage and just focus down whoever is closest to you/ highest priority. You can even focus tanks (in certain situations) because of the insane tank shredding this build does. So don't worry if you can only reach a tanky front liner in a team fight, as long as you have your core items and you are not a full 2 items behind you will do damage to anyone.

Stay close to your team because vayne does not do well vs heavy cc/ engage comps. It is really hard to fight their team when they are all on top of you and you have short range and a teeny role to get away.