I duck tape my gels to the handlebars. Take the tab of the gel and tape that down, so when you are riding you can pull the gel and it will already be opened. So far that has worked well for me. Good Luck! ;-)

I use hockey tape or athletic tape... also leaves no residue.

I think this basically shows that you can use whatever kind of tape you want, that's not the main point.

You have to be careful when you grab the gel to pull it free that you don't simultaneously squeeze all the goop all over your legs and bike. I've seen it happen and it was hilarious and kind of sad at the same time. That means maybe pressing with your finger to move the gel away from the neck. I have also found success taping the gel tabs to the top of my stem and letting them hang down behind the stem above the top tube. There's a million variations, do what makes sense to you and it's probably not totally stupid.

Sometimes people tape gels to their seatpost or to the basebar of their aerobars. Probably they've got different theories about aerodynamics or ease of access.

I put my gu into a flask and keep it in my pocket or bento box. No need to mess with packets and worry about dropping them and littering.

To throw my .02 in here - I put a little water in the gel flask - make it easy to get it all out.

Pre-tear the gel packet a bit, then lay the tab across the threads of your water bottle top and screw the cap on. When you're ready for the gel just pull, but remember you'll have a flappy gel pack on your water bottle if you use that bottle before the gel.

I guess I am old fashioned...I just put the packet in the back pocket and eat it when I need to. Then chase with some water.