I use eyelash glue, a friend of mine uses washable elmers glue. The eyelash glue is a PITA to get out, don't try to brush it out, but they stay very well. I've kept a whole stoned hairpiece on with just eyelash glue and had to work to get it out later. Elmers I imagine is easier to get out cause it's water soluble, but it doesn't dry as quickly so you'll have to be very careful when placing them. Eyelash glue gets nice and tacky quickly and they'll stay where you place them.