Doran help

[Voxsin]

My friend wants to make a  {Doran, the Siege Tower} deck any tips or deck post?

[Gorzo]

Not to state the obvious, but you'll want a lot of creatures will disproportionately high toughness and low power, like {Jaddi Lifestrider}. They are super cheap (mana cost and $ cost) and become doomsday machines when Doran is out.

You might want a few defenders/walls as well, as they have humongous toughness ({Tree of Redemption}), and then add ways to allow them to attack, such as {Warmonger's Chariot}.

[Almosteric]

 {Animate Wall} is another good choice to let those defenders do their business.  {Rolling Stones} is also good.

[Voxsin]

Ty ty

[Dudecore]

{Palisade Giant} comes to mind. I'm sure given enough time you can find a bunch of cool ones.

[MisterJH]

{indomitable ancients} {kraken hatchling} defenders like the one that mills for how many you control

[Dudecore]

Do {Meekstone} and {Crackdown} work? Rules experts hurry!!

[MisterJH]

Yes, doran does not alter power or toughness. Its a strange card though. Indeed it is

[Stoneco1d869]

I would also add creatures such as  {Sylvan Primordial} for reach. Not ideal with his mana cost, but again he is just an example of reach.

[Keyeto]

Do {Meekstone} and {Crackdown} work? Rules experts hurry!!

Absolutely! To emphasize MisterJH's point, Doran only changes how creatures deal combat damage, everything else that deals with power/toughness remains the same. Tat being said, if you're using a lot of walls, {Noetic Scales} might serve you well, as well as {Ensnaring Bridge}. If you can manage to get it into play, {Autochthon Wurm} can get really nasty, especially since it has trample, and {Jareth, Leonin Titan} is a really solid blocker, and an easy 7 damage with his protection!

Almost forgot {Sapling of Colfenor}! It can be pretty useful in a doran deck.

[Wsuryanjeska]

You want creatures with Infect. There are a few that have weak power and high toughness (sorry I don't know the names), and if you add those along with some spells that beef a creatures toughness you can eliminate people fairly easily that way.