My entire lower body is tight and this causes me to have a bad experience particularily with downward dog...I have a colleague who is a certified Ashtanga and Scaravelli yoga teacher...she's been spending time coaching me and we were, at first going to go straight into Ashtanga, but when she saw how tight I was, she reverted to some basics for stretching my legs...this has helped a lot...now I can do the Ashtanga sun salutations better, though I still definitely need work!

S

Hi Ayahuasca,
Are you familiar with Mukunda Stiles? His practice is on structural yoga. He has a book out called "Structural Yoga therapy." It describes in detail with illustrations which asanas to do for various complaints and the order in which to do them in. Also, you might want to check out his forum at http://www.yogaforums.com
You'll find that many have posted similiar concerns.
I'm pretty sure he'll recommend warrior 1 & 2, as well as side hip stretch (right & left) to strengthen those hamstrings. And trikonasana (triange) for inner adductors if they are weak.
Hope it helps.
namaste,
shanti