Sticking to a budget with a high income

Like a lot of people in this sub, I make a fairly high income ($235k annually). When I was broke, sticking to a budget was pretty easy -- I physically didn't have the money so it was an easy choice between buying some crap I don't need and buying groceries/paying rent

Now that I'm making really good money, I have no debt other than a federal student loan that I make minimum payments on since it's 0% interest, I put away a substantial amount for savings monthly, and I still have the ability to blow as much money as I want on dumb crap.

I want to spend less of dumb crap and cut out the lifestyle creep that has happened over the past year-ish so that I can put more into savings. What are some ways I can ensure I am sticking to a reasonable budget instead of justifying bad decisions with "well, I can afford it, I'll just put $1000 less into savings this month"?