Silicone earring backs for fine posts

[thefirstmrsdewinter]

I've tried my usual silicone earring backs (the kind pictured, with the round pad) with a new pair of earrings but the post is too fine and the backs just fall off.
Any ideas? I can't seem to google the solution.

In the past I've got a rubber pencil eraser, cut a little wedge off, and pushed it onto the earring post. Voila!

Well you get extra points for ingenuity but I need the round pad to hold the earring flat to my earlobe. Otherwise the butterfly backs that they came with are fine for just keeping the earring on.