^letting it sit does allow for the bubbles to rise and combine to larger bubbles, making the flick easier. What does brave the bubbles mean?
Another tip:
Suck in about a unit of air, and gently tilt the syringe back and forth horizontally, while slowly twisting, letting the large ~1 unit air bubble move from plunger to tip and around the barrel aiming your movement for the small bubbles along the inside of the barrel. The large bubble of air should slowly absorb the smaller ones. Once all are absorbed, hold the syringe upright, and pull the plunger back a little to remove the thin layer of liquid that usually forms in the tip both with this method and also with flicking, and then proceed to press the plunger so that the solution passes up to the needle tip. If you flick it once all the small bubbles are absorbed, before pushing the liquid to the tip, more small bubbles usually form. But tiny air bubbles are not the biggest issue, usually they just attach to the plunger once it reaches so far during injection, just try avoid injecting larger amounts of air.
The above methods are if it is air we are talking about. If there is froth, bubbles suspended in the solution and not just bubbles on the side of the barrel, like the frothed milk on a cappuccino, then there might be some nasty fucking shit in your dope that should at no cost be injected (f.ex. it could be some sort of oil or certain lipids that should not enter veins).
In any case (this is something I do with every single shot), put a few drops on the back of your hand in that neat little concave spot so often used for snorting shit at clubs, and taste the solution. Anything tastes off, do not inject. It is good practice to taste the solution before injecting, because once you know what a pure DOC solution should taste like, you can avoid a lot of issues and decide even before proceeding to IV whether or not you got baking soda, talcum powder, ground up instant coffee or whatever other shit some people use when gypping folks in street deals. Be safe buddy. Take care and one love to all!