Hey,
I did a fresh round a couple of months ago. I googled the videos and watched them a couple of times before doing it and played them the first few times of doing the injection, I suggest this as some injections you press to get an air bubble out, others you don't etc. Some you need to get out the fridge beforehand etc
As for what else I did. I iced the area for a couple of mins before injecting, I used a reusable gel filled eye patches that had been frozen, found it less messy than an ice cube. Tucked it in my knicker elastic while prepping the injection.
For injecting the way I found best was to inject was each side of the belly button, about an inch from belly button, alternating sides and trying to avoid the same spot.
I pinched the skin and pushed the needle in slowly till you could barely see any needle left (mine were short), never felt the needle go in, loosened the pinch ever so slightly and then slowly pressed the injector, once the injector was right at the end so full dose given I counted to 5, let go of the pinch and then placed my finger tips against my skin where the pinch was and withdrew the needle.
I found by doing it slow there was no or very little med leaked, by giving it the 5 seconds it meant no med came out of the injection site (tip a nurse gave me) and I didn't bruise or bleed as much on the times I held my skin down.
The bleeding was literally a dot so please don't worry.
Hope this helps and good luck!