I add some talcum powder inside the tire to help the tube find it’s natural lay when inflating. Seems to help as most of my patches are situated on the outer facing part of the tube. I seem to patch a tube 4-5 times before I need to permanently retire the tube for other reasons.

I carry two spare tubes as there have been times when I needed both. Such as when I unavoidably ran over a carpet nail strip and flatted booth tires at once. I’ll find the smallest tubes (ultralights) of the correct size to carry as spares. I used to fit undersized tubes to save weight, that worked fine when the tube had no patches, but when patched the tube seemed to stretch too much with respect to the patch and it peals and creates leaks. These were the only times I’ve had patches fail.

I’ve tried glueless patches a number of times over the years. A couple have leaked which erodes my confidence in them.

Make sure you are using the proper width rim tape for the rim channel. I’ve used Velox tape forever but now prefer plastic, non-adhesive strips with a snug fit. If the cloth variety get wet by riding in rain a lot it can take some time for the tape to dry out.