One of the biggest mistakes that people make when it comes to home renovation is they try to be cheap when they buy materials. However, you're going to get what you pay for. Take the advice of the professionals; if you're going to do it, do it. If you can't afford to do it, wait.
DON'T SKIP THE PREP
No one likes the tedious prep work that goes along with building, restoration and painting, but doing it can save you lots of time and money.
Measure twice...cut (or tape, paint, etc) once. An inch or even sometimes a half an inch can make a difference. And if your dimensions are off and it's not equal and symmetrical, you're not going to get the full impact and effect that you want.
GUT OR NOT TO GUT
Maybe you don't need to gut a room or home. Have a well-set plan before you start your renovations. You might be able to work around some areas. For instance, before you decide to you HAVE to paint an area, consider what it will impact...will the color work with the current furnishings, will you have to paint other areas, change other aspects of the room, etc
Make sure you have the right tools for the job ahead. If not, there are three big issues you may encounter
1.You can wreck the tool
2. You can wreck the project you're working
3. You can get hurt and wreck yourself
Be sure to pick the right fixture for a smaller space. Don't try to put full-size fixtures in a tiny, tiny bathroom. It's just going to be crowded. Look for narrower sinks and toilets to fit the space.
DON'T BE TRENDY
Don't go too trendy with your house. People often make the mistake of wanting to be too hip and trendy in their home by picking the latest, hottest, coolest things. However, trendy is short term and will look dated before you know it. Consider looks and items that have and will stand the test of time. Classic items, designs and colors will last and better serve your home.
Using the Wrong Paint Type
People often make the mistake of picking the wrong paint for whatever particular project they may be working on. There is paint for just about every surface.
Flat is for your ceilings and sometimes for your walls. Whereas your semigloss would be for trim in a bathroom or in a dining room. The glossy will give it a more upscale look.
The most important things you can have on a job site for your own personal safety are goggles to protect your eyes, ear protection to protect your hearing, gloves to protect your hands and good boots for your feat.
DO YOUR HOMEWORK
Know what you're undertaking before you start the job. Even if you're not doing the work yourself, know what to look for, what your contractor is doing. That way you can keep a close eye on the project and know when something's getting out of hand. It's important to do at some preliminary work. You want to be able to have enough information to know what questions to ask.
People sometimes forget about electric when they've been renovating because it's costly and it's hidden. Walk through the house with the electrician before you start to talk about outlets, where they are, where you want new outlets, three-prong outlets. Make sure everything's up to code.
The bottom line is if you do perform work without a permit and something serious happens, your homeowner's insurance will not cover it. Get permits!
SET A REALISTIC BUDGET
People often underestimate what it's going to cost to do a big renovation, and part of that is because they don't realize the biggest cost in a renovation usually is the labor. You never know what's going to happen once you start the demolition process. As soon as you open up a wall, you never know what you're going to find behind that wall, so you need to pad your budget, and you need to be realistic.