When it comes to home projects, there are certain things that make more sense to do yourself. Sometimes there are great financial incentives, other times it’s the ability to simply have it done exactly as you like it or the pure satisfaction from a job well done.

Then again, some things are just a nightmare. You may see a chance to save a little bit of money, then next thing you know you’re only a quarter way into the job and already realizing you’re in way over your head.

Have no fear. Here’s a guide to help you figure out when to DIY and when to call an expert.

DO: Paint Your House

Painting the interior of your house is something most anyone can do. Given the savings at stake — hundreds, if not thousands, of dollars — it is probably worth it. The sacrifice you make comes in the form of time and mess, but that should only be an issue at the very start. Anyone who has tried usually gets the hang of it pretty well. The finished product may not look quite as impeccable as a pro, but if you take the time to prep and add an extra coat, the results are going to be very similar.

DON’T: Electrical Wiring

Becoming an electrician takes a ton of time and a lot of studying. This is not something that anyone should expect to understand by watching a few YouTube videos. One wrong move, and you can put yourself in the hospital or the house into flames. This is electricity — don’t play around. Call a trained professional.

DO: Home Security

Home security, specifically video surveillance, is becoming more and more popular. One factor is the cost, another is the simplicity. Today, modern home security camera systems can be ordered online and quickly installed by a homeowner. The instructions are simple to follow and there are a ton of helpful videos on YouTube to watch if you run into any minor issues. Honestly, compared to even something like assembling Ikea furniture, installing a home security camera system is a breeze.

DON’T: Change Your Oil

This is just a mess waiting to happen. Sure, you can save a few bucks if you change your own oil, and some people really do take pride in working on their own car. But do you really want roll around on the ground and get covered in grime — maybe cutting yourself on some sharp metal — just to do something that can be finished in a half-hour down at the garage. There is something to be said for rolling up your sleeves and getting your hands dirty, but getting them filthy? Just to save $20 (or less) while giving up your Sunday afternoon? No thanks.

Being Smart About DIY

Saving money isn’t the only reason to DIY, there can be a legitimate feeling of accomplishment when looking at a well-painted wall or setting up a security camera system. Someone will do it if you pay them, but why not learn how to do something yourself?

Then again, you have to know when to say when. Certain areas, like wiring and electrician work, are only fit for real experts due to safety concerns. Other tasks, like an oil change, simply aren’t worth the hassle since having someone else do it is faster and so reasonably priced.

With these and all other potential DIY projects around the house, there always has to be some calculus involved. Risk vs. reward vs. savings vs. time vs. several other factors. The choice is yours — but use some common sense and remember to consider it all before you decide which way to go.