{It was not my favorite.}
Anyway, sometimes when I was baking, the kitchen would get REALLY WARM and my cookies would come out over baked. So, one day, I invested in an oven thermometer.
{They're really inexpensive. This one is from Target and was about $7.}
What do you know, that oven would sometimes cycle all the way up to 500 (!!!) before cooling back down to 350. It wasn't my fault! It was my oven!!!
It's easy enough to check, just hang the thermometer inside your oven, let your oven heat up for about 15 minutes. You'll want it to come to the preheated temperature and stay there for 10 minutes or so, then check it.
Once you know if your oven is running cool or hot, you'll be able to adjust your oven temp when setting it.
One more tip....check to see if your oven has any hot spots.
Blaming baking problems on my oven? Works for me! ;)