It's very tricky.
If you find a lawyer that sees many deals, then he/she likely knows many VCs and knows who butters his bread.
If you find a lawyer that doesn't know many VCs, then they likely don't know as well the in's and out's of term sheet tricks.
More fundamentally, the problem is that founders are technical (by and large), and they are up against people who do term sheets for a living. It is a very asymmetrical-knowledge situation.
(BTW, if the lawyer does see a lot of deals, I would wonder how much of their business is representing investors, and how that colors their thinking. Their duty is to their client, but it's just human nature to see things in the same terms as your client base.)
These negotiate for a living, but investors shouldn't be intimidated. Take your time, think the thing through. DO NOT BE AFRAID TO SAY NO. Always have a plan to walk away, and never get committed beyond your comfort with the terms of the deal. Always have some plan to bootstrap, if only to prevent psychological commitment to _this_ funding deal.
I'm sure the fundraising process is a pain, but a lot of the preparation and strategizing is stuff that management should be doing anyway.
I had an experienced and well-recommended startup lawyer completely overlook a bullshit clause in a term sheet which he said was 'complete standard'.
it was a friend of mine who had experience with similar who pointed out everything the lawyer missed
For example, a couple of days before our first round of investment one of these guys told us "you do know you'll be expected to sign personal warranties to the investors" - something our own lawyers had managed to forget to mention (and strictly speaking they might have been right as they were, of course, the company lawyers). NB Personal warranties seem to be (were) a common thing required in the UK - I believe they aren't used in the US.
[Edit: I suspect we were made to do quite a few things that would look crazy to folks from the US - our first round of investment was in '97, hopefully things have got a lot easier in the UK for startups.]
I think a good strategy would be,
* Spend an entire night reading the term sheet yourself. Your interests in a good outcome (as founder) may uncover details others have missed.
* Ask other founders (who've previously taken investment) to look at the agreement too. A fresh set of (experienced) eyes can't hurt.
* Make the most of lawyers. They've certainly been around the block too, but the trick is to tap their knowledge and not incite a fee-charging frenzy.
* Lastly, search for terms you don't know and try to understand everything. After all, for most of us, it would be one of the most significant moments of our lives.
Wilson Sonsini is pretty popular up in the SF Bay Area. Goodwin Proctor for NY-area startups.