I switched to the self tie garters some years ago. I find them more comfortable, and prefer the look to that of the tartan flashes.

Tartan flashes make an excellent sample swatch. Take a flash with you when purchasing ties, shirts, sweaters, etc. for wear with your kilt. Some colors/patterns just shouldn't be worn with some tartans. Better to find out in the store than to take it home and discover you are going to have to make another trip to the store to return the item.