I have found the Cyclami patches to be the most robust. I'm running tubes that have been patched 3x each with the Cyclami patches and they still hold well.
My process at home for fixing:
Inflate tube and clean with soap and water quickly before it loses shape/pressure
Find hole, dry area, circle with permanent marker.
Scuff area with fine sandpaper(180-300ish works) in all directions
Clean area with alcohol, wash hands and dry completely
Press Cyclami patches onto hole and press firmly for 30sec-1min
Lay tube with the patch flat inside a book.
Stack a bunch of shit on top of the book to act as press.
Leave overnight
Inflate in the morning and hang tube to check for any leaks, squeeze gently throughout the day(s).
Put back in wheel, or into saddle bag.
On the Road:
Scuff puncture and surrounding area with sandpaper
Clean area and fingers with alcohol pads
Press patch onto area and hold for 1min
Reinstall tube and make it home.
If tire holds air in the morning then I dont mess with it. If its losing air then I do the above method with new patch.