I change my guitar strings every month , and for some reason no matter how long they have been on my guitar when i decide to give it some at gigs they just snap.
I've tried all sorts of ways of putting the strings on but they have all been the same.

I have an Epiphone Les Paul Standard and I use Regular Slinkys.

Any help will be appreciated

Try holding your pick lightly and strum softer! Even with heavier gauges if you strum to hard your strings will break. To make your strings last a little longer try cleaning them after you play.
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Every month is so much more regular than me. Everytime I restring mine I'm surprised at how much dirt there is on the strings.
Anyway, it does sound like you might need to look at playing a little softer, maybe try both lighter and heavier gauges, because heavier gauges will be bigger, but lighter gauges might be a bit more 'elastic'/bendable, and that'll help them not to break.

You must be about 3 miles away from me at most.
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I used to use the lower gauge but i though they didnt give me the sound i wanted.

And in my opinon i don't even think i strum that hard.

I watch over bands hit the **** outa of their strings and do **** all...

Where abouts in watford you from Matty?
You could have some rough edges on your bridge (depending on where the string snaps) which rub away at the strings causing them to weaken and then when you decide to 'give it some' at a gig, because the strings are weaker than they should be then they simply snap.

If they snap in random places then try another brand like daddario. If that doesn't fix the problem then go up to 11s or 12s and if that doesn't solve your problem then i think you're strumming way too hard
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LP TOM bridges when new tend to have edges on the saddles. I use a nut file to smooth them out but a nail file would probably work. And a month is a long time if you play guitar everyday. Another trick with LPs is to wrap the strings over top of the stop piece. It puts less tension on the saddles. It really cut down on the strings I broke. I use .10 ddarrios and 1mm heavy picks and am really hard on strings and dont break many anymore.