how to get the twinkle eyes on blind bags?

[Varkolak]

hello, i've noticed some people use little rinestones on blind bag ponies, do you just glue them on? use modpodge? do you have to carve out some of the eye socket? please share with me your secrets and i can't figure it out. same with g1 pony baits. i tried putting them on a pony, but they stuck out like bug eyes.