From reading a lot of VC blogs, the thing that affects their valuation the most is competition. I think the most important thing you can do for your deal is get a competing bid of some kind, any kind, any outside interest at all will do more for the price than you can do within the confines of the deal with company x. This may sound difficult and it is, but I think it's absolutely critical.
Yep, the two most basic things to do in any negotiation are start high since the price will only be negotiated down and develop your BATNA (best alternative offer).
