Having have had providers cancel on me last minute and scrambling with limited days left in Japan, some tips:
1) Don’t panic! If you’re outside, find somewhere to sit down with a computer or phone handy.
2) I always have prepared three shops at a similar price range which I can be certain of their quality. Don’t walk into random shops.
3) Go to Cityheaven and look at the girls who are sokuhime at these three shops. Make a shortlist of 3 each. Check if they have SNS and see if they are open to SNS reservations.
4) Walk into each shop and ask for any of the three girls. Beggars can’t be choosers - you may have a certain ranking in mind, but you take anyone who’s available you’ve already shortlisted.
5) If they aren’t available, walk to the next one.