What are some lifestyle changes that save money?

I can think of a lot since I have been brought up in a household where money certainly didn't grow on trees, but I'll focus on three main areas.

Shopping for groceries:

• Pay with cash: the psychological effect of having something physical being taken away from you, leaving you with less of this thing than when you started hurts a lot more than popping a piece of plastic in a machine and suddenly ending up with multiple bags full of food.
• Always make a list: Before you leave the house, be very clear about what it is that you need and what it is that you want. Populate the list more with things that are missing in the kitchen/room rather than things that would be a cool nice to have.
• Shop late: Find out when the local grocery store starts reducing the prices of items. It will probably be around some time in the evening. Here you can snap up pretty good deals on perishable items (e.g. pastries which were baked in the morning). Be sure to eat these items on the same day, or freeze them. Sometimes you've got to be wary of reduced items though - reductions may not be that much compared to the original prices, so you've got to always remember to ask yourself "do I really need that?"
• Cook: Ready meals are not cheap. Buy common ingredients, e.g. onions, chopped tomatoes, rice, pasta etc., and cook your own meals. You save a phenomenal amount of money and end up healthier since you control exactly what goes into your meal.

Mobile phones:

I pay a minuscule amount of money for my phone. I bought it about 4 years ago, it cost £60 at the time, and it's on Pay As You Go on the Three network. I havealways avoided phone contracts like the plague. If you are on PAYG:

• Top up when you need to: This literally means when you've ran out of credit. With most contracts, regardless of your usage you still pay the same fixed amount every month. Topping up £10 for me is enough forseveral months worth of usage.
• Text more than you call: Texts only cost about 3p for me. WhatsApp is an even better option. Whenever a WiFi hotspot is in range, I'll make use of it. Other forms of communication are done via my laptop or speaking to someone face-to-face.

Clothes:

This one's pretty simple, but specific to guys:

• Wear black t-shirts: Black goes with pretty much anything, dirt isn't as easy to notice on them, and they look pretty sophisticated without any expensive brand names on them. I take things to the extreme and wear a black t-shirt out every day, along with some form of black jeans, and black trainers. As a side effect, it also saves time in the morning figuring out what to wear.