I take a breath and say, "G-d. Whatever it is that I am really looking for in that woman, please let me find it in You instead (soon?)." And trust Him.
Sometimes I'd daven for the woman's needs and future (after turning away), and awaken that goodness in me that really wants the best for everyone I know - even for those folks that I may want desperately to use. Then, when the same lust would occasionally return 2 minutes later, I'd daven for them (and all their needs, futures, children, health and satisfaction out of life, and to be saved from all the bitter suffering that many people have, etc) all over again. At times, I have done this 4 or 5 times, when needed. An SA old-timer named Jesse (nicknamed the "Bozemann Hammer") used to say, "I can pray longer than I can lust", or something like that...
Sometimes it was enough for me to say, "well, that's not my chelek. It's just not my chelek in this life at all..." And knew that acceptance of that fact was just a pain I'd always have to bear, for there will always be a gorgeous woman out there who I'll come in contact with. There is no shortage of beauty in Hashem's world... so what better time to accept my limitations than right now? It hurts, period.
Sometimes I'd fail at all these or forget them all. Then I gotta make a phone call and admit it to an SA guy, who will hopefully commiserate and just say "thanks for sharing". (It seems to be useless and counterproductive to be reminded, "well, you'd better not do anything with her, it's evil" or whatever. My body revolts from finger-shaking.)