Dave Ramsey's Total Money Makeover book lays out how to set up a monthly and weekly cash flow budget. You basically look at ALL of your regular expenses over a year and break them down into weekly and monthly budgets. For example, think about what you spend for Christmas -- this is presents, extra food for dinner parties, a couple of road trips (gas, hotel), etc. Now break that amount down into a monthly allotment. Take the cash and stuff it into a "Christmas" envelope each month.
Take auto tags and inspection. These things aren't a surprise - you know you'll be getting them every year. So take that $200ish or so per year (ours is about $60 per car for registration and maybe $40 each for inspection), and break it down monthly, put it in an envelope.
Same thing for birthdays -- your family, friends, the people you buy for regularly, plus a few extra invites... This is where it can be difficult. You may be used to buying a $20 gift for a friend's kid. If you look at the total on birthday gifts, it can get pretty high. We've limited the amount per gift to $10.
The book lists all of these annual things -- anniversary, family vacation, homeowners insurance and taxes, school supplies.
It also lists your weekly and monthly expenses to consider -- groceries, paper products, toiletries, hair cuts, eating out, week-day lunches (if your husband eats out at work), car insurance, life insurance, utilities, cell phone (all the regular bills), debt payments, diapers, weekend "fun" money, etc.
You're giving everything a category. The problem probably isn't that you're an extravagant spender (we weren't), but that you just don't have a cap on all these different categories.
Once you look at all the amounts, you can move numbers around as you work out what's real. Honestly, though, there are some trade-offs to make. If you want more in weekend fun money, maybe you give up a couple fast food lunches. Maybe switching to generic diapers will leave room for monthly eyebrow waxes... :-)
If you need help setting up your budget, I know an excellent budget counsellor in Denton. She was free when we used her, but may charge a nominal fee now (it's been 5 years since we first started seeing her). She can set you up on this type of budget and literally hold your hand through it for about 6 months.
Hope this helps!