With scissors I cut the transfer to the absolute edge of the design, in my case the Imperial Fists logo because otherwise the transfers are too big to fit nicely on shoulder pads.
Whilst the transfer is soaking in water I slightly dilute a little PVA glue, and brush some onto the shoulder pad.
Then the transfer, with most of water removed by touching the transfer to your finger, is positioned in place. I find the sculpting tool is handy for lifting and initially placing the transfer.
I then carefully with a small paintbrush, flatten it as best as possible, removing excess glue as I go.
This I then leave until the glue is half set, then with more PVA on a small brush I'll coax any more under anywhere that needs it in the transfer and again do my best to flatten it nicely. I also like to brush a layer of PVA over the transfer to help protect it.
After letting dry for a little while, I add further protection by brushing some of the GW Gloss Varnish over the transfer.
Heresy grows from idleness.