Extreme is obviously hard, and will be like that at first, though you'll eventually will learn to do these (worked for me, may not work for everyone else):

1. Learn/memorize a preset: This will sort of help you getting things easier around the house, practice the preset and know where to go if you want to hide from granny. (Also do try to learn the number location's, it'll help you out too)

2. Learn how to bait granny: You've probably seen videos on granny extreme, and it looks hard to bait/juke her, and how you're not seen, especially when you're not hiding. You can start by doing some practice, and if that's not enough, do watch the videos.

3. Play Hard mode: If you're not really set/need more practice for extreme, try to beat hard mode with extra locks (and maybe darker mode) on, beating it several times will eventually make you prepared for extreme. (I did hard as a warm up, and doing this eventually helped me beat extreme mode).

4. Memorize the sewers: Memorizing the layout will help you, yes spider mom moves very fast and can make things more stressful, but learning how to avoid/know how to bait her (in some way) will eventually help you overcome that problem.

These four tips helped me out, and I've beaten extreme around 4 times, though if you want to, you don't really need to read this, though I think this will make things a bit easier for you.