Here is a bit of a sampler pack to try out. It contains 12 egg flies.
The first four are muppet patterns with the lead dumbell eyes for a fast sink. A lot of people use a weighted nymph above but this is a good alternative if the trout are targeting eggs. They are all size 10:
Champagne Muppet with a Fluorescent Yellow Dot
The other eight cover the basics wit a few brightly coloured variants. They are all size 12:
Champagne Globug with Fluorescent Yellow Dot
Chartreuse Globug with Red Dot
There are so many ways to catch a trout on a globug. The most common way as stated above is to tie a globug to the bend of the hook of a weighted nymph or muppet above. That is generally fished in moving water under an indicator. People tie them behind or in front of streamers and buggers using a weighted line or floating. The possibilities are endless. Stillwater nymphing with an unweighted nymph and a globug in places like Flaxy Lake used to work. I might have to try it again this winter.