Home made cloning tray

Hey just about to take a couple of clones for the first time, i was going to cut a 2 litre bottle in half use the bottom half to place over the clone, will this work or do i need to cut some vents in it for air circulation, also does any1 know if i shd keep them in light or dark immediatly after cutting? cheers

use the side with the lid and unswrew it so that air can get in..keep in light for 24hrs till roots show

thanks so much for your help + rep