2
Are we talking something like a major new look, something bold and daring, or just the average run of the mill haircut?

Personal appearance is the ASC. Doing something stupid to yourself is the 12th house, getting a bad perm that causes the hair to all fall out, that's the 6th house. Lawsuits are the 7th house. Doing something nice that everyone enjoys, that would involve the 5th house. Smart ass comments are the 3rd house.
Mark F

3
See if you can find a copy of Vivian Robson's 'Electional Astrology' on line. This will tell you the conditions for getting a haircut, i.e. keeping it long, short, etc.

4
Generally speaking, choose to have your hair cut on a waxing Moon for your hair to grow faster, and a waning Moon for your hair to grow more slowly. It's odd but true - it's always worked for me!

For a pleasing style, I'd say aspects to your natal Venus might be important - at least avoid a haircut when there are negative Mars transits to her ;)

I got my new haircut on my recent Sun/Jupiter trine and I have to say, it turned out rather well! But maybe that's just the general benefic influence of the transit! My Venus wasn't recieving any transits at the time.

Let us know how you get on :)

5
farmers almanac.
family's been using if for years.
has lots of nifty "timing" for everyday things as well as haircuts and buying, selling, planting, reaping......etc.

6
for some reason i do not understand haircuts during a moon void of course tend to turn out well. but you got to let the hair dresser do what he wants, not push through your own plan.