I reread this entire thread, "What small things did you do TODAY to save money?" and collected the basic themes and ideas from the first 78 pages.
Not surprisingly, the overall messages are: nothing is too small to optimize, rethink "normal," challenge your assumptions, and you can learn and do more than you think you can.
I hope this is helpful. I had fun compiling it. Of course, the list doesn't contain every idea possible and certainly NOT every idea on the thread (read the thread, there are amazing, very specific ideas). This list is meant to give a general idea of the kinds of things frugal people do and how they think on a daily basis. I left out some themes like cars/driving and investments/work issues because they are well covered on other threads.
Of course, essential reading on "small things" is the MMM classic:
http://www.mrmoneymustache.com/2011/08/01/a-millionaire-is-made-ten-bucks-at-a-time/Theme 1: Learn new skills, DIY everything you can, and build your frugality musclesPrefer handmade/homemade over store bought
Make do with what you have, don't just go out and get more
Wait/rethink/research before buying
Read the "What small things did you do TODAY to save money?" thread on the MMM forum for specific ideas that apply to your situation
Try your best to communicate better with spouse/significant other/family on financial goals
Make clear financial plans for yourself and with family
Break a bad habit (smoking, shopping, etc.)
Have a "no spend" day
Speak up for yourself, don't be afraid or ashamed to be frugal
Speak up when there is a problem with a service or a purchase; return things that are substandard for a refund
Always check your receipts and invoices for errors
Ask around (friends, coworkers, family, neighbors, MMM forums) for help, information, free stuff (AND offer same to others!)
Barter services (dog sitting/fixing things/chores/airport runs)
Use a coupon
Maintain and fix things yourself
Accept free things
Investigate the problem before throwing money at it or before hiring an expert
Try to problem solve before acting/spending
Google/You Tube before spending and to learn new skills
Develop your cooking skills (one of the most important frugal skills)
Learn a new skill (haircutting, sewing, oil changes, anything!)
Use muscle power before machine
Sew/repair things
Make gifts rather than buying them
Rethink material gifts and give an experience, do something for someone, write a letter
Reuse things for other purposes to delay throwing away (e.g., plastic containers, towels become rags, etc.)
Learn to cut your own/family's hair
Do your own/other people's manicures
Maintain your pets nails/hair yourself
Do holidays, birthdays, or other special days NOT on the actual day to save money on restaurants and to not pay full price for other holiday-related items
Sell things on Craigslist, eBay, used bookstores
Rethink all purchases
Delay purchases
Don't go in stores!
Realize everything is a "small" thing
Check out Freecycle.com
Look into free things from your local area/town (e.g., mulch, free cultural events)
Pick up change off the ground
Trashpick, look for things on the side of the road
Pick up cans
Be organized to avoid impulse purchases or buying duplicates
Scrutinize purchases and find ways to reduce
Shop around for everything (gyms, classes, grocery stores, insurance, prescriptions, cellphones, internet) to find best price
Ask for a discount everywhere (maybe even at the dentist!)
Check all recurring charges and try to find less expensive plans (insurance, cell phones, internet)
Investigate used, damaged, or past prime goods/food
Challenge your property tax assessment
Renegotiate any subscription (cable/internet/magazines, etc.)
Theme 2: FoodForage/glean and hunt/fish for free food
Eat leftovers
Repurpose leftovers
Use up what you have
Use up the pantry
Can/preserve/freeze food
Freeze leftovers so they don't spoil in the fridge
Eat less meat
Investigate new grocery stores to check prices
Try the cheaper brand
Check grocery sales flyers
Build your cooking skills
Bring your own food to work/on car trips
Make baby food
Eat beans
Buy the cheaper fruits
Use crockpots
Use less coffee or tea, reuse teabags/coffee grounds, carefully measure how much coffee/tea you actually need to ensure you don't use too much
Eat free food from work events
Make a price book
Garden from seed
Exchange recipes with friends/people on MMM forums
Regrow green onions from the roots
Batch cook/make a lot at once ("hypermile" the oven, can, freeze, preserve)
Learn to make your family's favorite dishes at home
Learn to make "gourmet" or complicated things that you never thought you could (beer, hard cider, mead, chai tea, Asian food, frappucinos)--you can do it!
Make your own coffee, pizza, yogurt, hummus, bread, burritos
Grow herbs
Take advantage of chocolate sales days (2/15, 11/1, 12/25)
Theme 3: Fun and entertainmentTry a staycation rather than leaving your neighborhood or town/city
Search out local fun, free community events
Read a book
Entertain people at home, but don't buy special food, make it yourself (use your pantry)
Have a picnic
Listen to the radio
Look for free events at museums
Exercise in nature
Volunteer at cultural places for free entertainment
Take joy in simple things (seeing friends, walking the dog, walking in nature)
Use the library!
Check out ALL library programs. Libraries have more than books: movies, music, books on tape/CD, classes, internet/computers, magazines, used book sales, tax advice, even exercise classes
Theme 4: Home and home energy useStay home
Use a programmable thermostat
Keep heat low
Keep A/C temp up or turn off
Use LEDs
Don't use dryer, hang clothes on inside or outside clothes rack/line
Cancel cable
Turn off or unplug electronics
Make your own cleaning supplies
Shower at work or at the gym
Don't use paper towels
Gather rainwater for gardening/to flush toilets/wash laundry
Use rechargable batteries
Rent out a room, parking space, or things you own
Look into thermal gain or loss through windows
Theme 5: Personal care/clothesWear clothes more than once before washing
Cut/color your own/family's hair
Do your own/other people's manicures
Maintain your pet yourself (hair, nails, hooves, washing, etc.)
Use less soap/makeup
Repair or have things repaired (clothes, shoes, coats)
Resole shoes and boots