I usually Fix my monthly budget as per my needs and allow some money extra for use remaining money will be saved in my Saving Account.
Mostly I'll try not to spend money than my budget.
1) Work out what you can afford to save each month
2) open TWO savings accounts
3) by direct debit set up a small payment - say 1/3 of your total into savings account no.1 - this is your retirement / total disaster money and should NOT be touched til you retirement
4) by direct debit set up a payment of the remaining 2/3 of the money to savings acount no.2 - this your money for holidays. emergencies, car repairs and the like
I put money in my savings account, and don't spend it unless absolutely needed. The last time I took any out was for a $850 car repair.
Every month, my savings account gets 100 bucks (via direct deposit from my paycheck).
My 401k gets 20% of each paycheck.