Here's what I've discovered:
1. Finding a good fit with a critique partner is essential
2. Having multiple critique partners is essential
3. Staging your critique partners is essential
4. Providing thorough critiques in return is essential
Today, let's tackle #1, and then tomorrow we'll address #2, and so on.
What is a "good fit" and how do you find it?
First, you really need to establish critique styles. If you are brutally honest and your potential partner is passively nice... the relationship could be painfully short lived. You need to agree to the format of the critiques. Frankly, I prefer giving and getting the brutally honest feedback. I figure, how else can the ms be improved if there isn't honesty? Now, understand, as the author, you don't have to agree with the opinions of others, but I think you need to at least consider it.
Second, you need to test the waters of your writing styles. Sometimes authors with completely different styles can make excellent partners, but sometimes not. So, before committing, read writing samples of the potential partner and share some of your writing samples with them. If he/she writes with long flowery descriptions and you barely write any descriptions, your two styles may drive one another crazy and prove to be counter productive. But, on the other hand, if your personalities mesh, you may be able to utilize your differences to strengthen each others writing.
Third, observe some of your potential partner's critiques of other people's writing samples. If you like what they have to offer, pursue the opportunity.
So... where do you find these potential critique partners?
I've tried several methods, but I have found the "Weekly Chapter Challenge" Group and the "Critique Corner" Group at http://community.writersdigest.com/ to be the best resources for critique partners. So, check the site out, post some of your writing samples to be critiqued, and critique other samples. Then pursue potential partnerships with people you connect with there.
Another useful place to find critique partners is at writers' conferences, especially ones where you get a taste of their writing abilities, but again, you need to follow the steps above, because even if someone is an excellent writer, it doesn't mean they'll be an excellent critique partner.
Where did you find your critique partner? And, what is your best tip for finding a good fit?