If you haven’t added a studfinder to your toolbag, now is the time. The days of putting eight holes in the drywall before you locate the stud are over.
There are numerous occasions when a studfinder is invaluable. For instance, the other day I was installing crown moulding in a finished room. With the studfinder I was able to locate a place to nail so that the crown doesn’t sag later like it did at the house from this post.
It’s also helpful when hanging heavy objects or installing a bookshelf or even a baby gate that you want to hold when the kids are climbing over it. 
Basically, you just press a button the studfinder and slide it across the wall. When it finds a stud it lights up and even has a beep to alert you. As you can see in the picture, they are so easy to use so that even my 4-year-old could go around the house finding studs.
I’ve got a Zircon StudSensor SL, which is a fairly baisc model that sells for around $15 at Home Depot. There are some that get quite fancy and also find live wires within the wall and other hidden items.
Next time you want to hang a heavy mirror or bookshelf that won’t give you the drop, make sure you find the studs first.
-Peter
