I only take injectable because that's the only form I can affordably access given my unfortunate situation ¬.¬ I would have taken the dissovable pills if I could have them.
Oddly when I started my HRT I was extremely depressed and nearly suicidal again I was habitually cutting myself so jamming a needle into myself wasn't a problem... Oh boy is it a BIG needle. 21Gage 1.5inch long (Thick as a pencil lead)

Now however I'm not depressed but I do pout and whine about having to take my shot. It hurts and it's time consuming (taking 10-15 minutes) and it dose need abit of concentration rather than jamming a tablet under your tounge.
My intital changes were quicker than the average (boobs were notably forming after 3 weeks as opposed to 3 months) but overall I'm quite flat chested I don't think I got specifically better results than I would have with any other method.
I don't know if I'm allowed to tell you howto inject... I wouldn't mind but I'm not sure what the admins would think. I personally learned howto inject myself by asking steroid using bodybuilders howto inject and they showed me howto do intramuscular injections. And comfirmed it by checking the FTM's doing it.
Of course with the Bodybuilders their attitude was "Huhuhuh don't you think you should train abit first small fry? before you switch to steroids." I explained what I was doing different, they were accepting if alittle "O-o oh wow that's quite a subversion" suprised.