#1- Great idea! #2-Hmm. Someone did a REALLY nice job on these. For me, the screw top needs to be hidden, My ocd says NO NO! Could do beaded trim, embroidered ribbon, embossed metal strip, strand of pearls wrapped round & round, etc. Beautiful!
These glittery mason jars turned candle holders would make such charming centerpieces. They're inexpensive, easy to make, and you could customize them fully to your theme and color scheme. Instead of (or in addition to) hearts, consider your monograms or use them as table numbers.