Wait and seek out the best possible clinic, instead of going with the first and closest one. Sometimes the best aid you can receive is only available beyond a couple borders, especially in certain countries, in which case plans to move elsewhere on a permanent basis tend to sync up well with one's transition.
Also, medical professionals are NOT always looking out for your best interests or even your welfare, despite their job description. The term "unprofessional" exists for a reason, and can easily pop up when the person in question has hidden, irrational prejudices. Also, trans people experience hideous amounts of said completely irrational prejudice, often for no reason whatsoever.
And also, be constantly aware of your environment. Can help tremendously when you're trying on clothes when alone at home or late at night, in case people who don't know that you're trans and/or would not be OK with it decide to suddenly return home/wake up and go get a drink or a late-night snack. And close the damn shutters if you have neighbours.