I just use a tissue doused in isopropyl before the injection and also after, to disinfect post-injection?

pretty much the same - i use those round cotton makeup remover pads instead of tissues (to avoid tearing). i just hold it to the neck of the isopropyl bottle and shake once or twice to get the pad damp but not soaked, and use separate pads for disinfecting the rubber stopper and my skin. disinfecting again after the injection is new to me - i just slap a plaster on as quickly as possible after removing the needle.