A couple of tips here..
Take the insulin out of the fridge before and let it reachi room tempreture before filling cartridge (I generally take a new vial out the day before strarting it, then leave it out while it is in use)
When injecting the air into the vial, I turn the vial the right way up, so not pushing air through the insulin.
Tap air out before you start, and durning primeing
Check the cartridge frequently, prime out air bubbles if you see them..
I always wear my pump with connector facing downwards, then if there is any air bubbles in the cartridge they should stay up the other end out of the way of getting into the tubing..
With practive you will find that the bubble issuse will get better and less of a problem, it's early days at the moment