Do all your layout for a home project on blue masking tape.

Lay the tape, mark your marks with sharpie, that way it's easy to visualize where things will go, if you don't like where they are, remove the tape and repeat.

That way you don't end up with 40 extra lines and marks when you arrive at the final layout. Works for walls, cabinets, hanging pictures or tvs, especially well when there are two mounting points on the back of something, tape to the back of the mount, poke holes where the screws will go, remove the tape and position on the wall where the thing will go

Make cardboard mock ups of small stuff to get the right size, check with the cutout before you go to install, for example a medicine cabinet in the bathroom.

Choose all your materials for finish before you start the project, at least then you'll know how everything will work together once it's nailed to the wall

If you go to HD or Lowes for fittings or fasteners or lumber, get one extra or 10% extra just in case, it might save you a trip or two back to the store, return what you didn't use at the end of a project, returns are easy, four trips to the store in the same day to get the right fittings are a huge time sink.

Put one extra fastener in if you're worried about strength of mounting something, say a stair hand rail, or cabinets. You'll be a lot better off with 7 screws than 6 and a cabinet on the floor with broken dishes.

Make better decisions when buying fixtures for your home, an extra $25-60 or even$100 can save you a lot of headaches replacing low grade stuff, you have to think about it long term. For example when choosing a garage door opener, get the $230 liftmaster/chamberlain instead of the $180 genie.

Seal openings in the exterior of your house extra well for air tightness, insulation helps a bit regulate temps but if you're house leaks like a seive no amount of insulation is going to do you as much good as making sure the inside of your house isn't wide open to the outside, bugs and roaches love to climb in through those spots, too.

Glue is stronger than nails, the pin nails you see in cabinets and furniture are just there to keep everything in place until the glue dries