Dyaplugs for trailside repair. I keep them in a side pocket for quick access. I’ve never used one on my own bike but they’re brilliant on the wife’s bike. Lake District rock has a habit of popping little holes through, so just shove in a dyna plug and you’re back away.
Once home then it’s 4mm or 6mm car tyre mushroom plugs – proper ones that need bonding to the inside of the tyre. Make sure it’s dry, sanded, cleaned with IPA then roll it down very hard with a patch tool. I’ve got a few repairs over a year old now and they’re perfect still. Nothing older as the tyres are usually wrecked and replaced by then.