This is one change that can save you alot and help you to follow your budget. I will admit this was a foreign concept to me. I had always had either a credit card or a debit card with me and I never used cash. This has also been the toughest change for me. Some weeks I will do really well with this, others I will not.
What I try to do each week is have 4 envelopes:
2. Gas - Cars
3. Dh Fun Money
4. Me Fun Money
Each payday I take out the budgeted amount for each envelope. I then make an attempt to not use a check, debit card, or credit card until the next payday.
This does not always happen because to me using a debit card is much easier and more convenient that paying with cash. With cash I worry about not having enough when I go to pay vs. the ease of just swiping the card.
Switching to "cash only" does work very well for me. Because I worry about not having enough cash at the checkout I do not put unnecessary items in my cart. I think more about what I am buying. It is also harder to spend when you physically see the money leaving your wallet and you know when the money is gone there is not anymore. It makes the money more real and you more accountable.
I know I need to get back in the habit of using "cash only" again - one thing I am going to try is having a small calculator with me. I can then keep track of my total so there will be no surprises at the checkout.