First tip. Buy an oven thermometer. You can get one for a few bucks. It is very common for domestic oven thermostats to be wildly inaccurate. I have used one for decades and often lend mine to people with similar complaints to yours. It always turns out the oven is lying about exactly how hot for you it is.
I personally am a huge fan of the $20 1400 watt turbo ovens. I slow cook salmon on the wash setting. Awesome.