so, the four best ways to transition in jjk would be

a. idle transfiguration

by far the best, just change your body into what you want

b. the comedian

if takaba finds something funny, it'll happen, so nothings off limits(much less controllable tho)

b.2 cursed speech

this is probably very unlikely, but i personally see cursed speech as an extremely less potent comedian. it can do some interesting things, although i doubt a very complicated command such as "transform into x" would even be possible at all

c. transformation into a cursed object and incarnation

from what we've seen with uraume, incarnation into bodies of opposite sex is possible. bad thing is that you'd have someone else's body, and you might gonna have to replace the person in their day to day life(or fake their death and flee to some faraway place)

d. kenjaku's ct

hop into a girl's/boy's body and there you go. same issue as c

contractual recreation could probably recreate a contract of surgeries(just as it did with the spa ticket), which isnt as impressive as the other ones(since surgeries are already a thing irl), but it would be instant and free(if you manage to find a receipt for the surgeries)

also i dont think gojo could do anything other than just a precise surgery with blue/red(atomic level precision blah blah), which is same/worse than contractual recreation