Another suggestion I didn't see mentioned is either:
A. Covering up one of the air holes with your finger when you take a puff
B. Plugging one of the air holes with a toothpick and breaking it off, wax, or some other substance.
The air holes are on the collar on the bottom. I just use my finger personally, no point in mucking something up that cannot be undone but if you find you always have to put your finger over an air hole, permanently plugging it is an option.
Just don't cover more than one, these need air flow to work properly and choking it will have adverser results.
p.s. I personally have never taken out flavor wicks or removed or changed around silicone.......never seems to work for me and seems to create other issues.
EDIT: some of these fixes work 40% of the time or less so they technically work but they don't really work.