Yes, all of the above. In addition, don't shake the vial like it's a can of spray paint. lol! If you have that habit, and can't break it, let it settle before drawing up the oil.
You can take the vial and swirl the oil around, and that should prevent the air bubbles.
I untwist the pin I used to draw the oil, and put on a new sharp pin for the injection. While the pin is off the syringe, you can push the plunger up, watch the oil go to the top, and that will help rid the larger bubbles. (do not break sterile technique by touching the top of the syringe, or new pin with bare hands though!)
Screw the new pin on, and push the oil to the top, letting some oil run down the pin for a lubricant for the injection. If there are any small bubbles left (there probably won't be), just ignore them as they're insignificant for an I.M injection. You'll see in time that this will become an "artform" for you. Good luck building mass or cutting!