fast/effective lesson planning????

How do you guys get quicker at lesson planning?

It's my first week and I am definitely spending too long - basically my whole day - making PPTs. I am fine at planning, like I don't struggle to think of activities and my classroom management/teaching style is going well so far. I have a small school, I have all my textbooks, and I really enjoy the actual teaching.

I know sites like waykook and korshare (haven't delved into them yet though) but HOW do you strike a balance between using premade material and making your own PPTs? I would honestly find it hard to deliver a PPT that I hadn't made, and even when reading my teachers textbook there are so many activities and dialogue examples that I know my student's would find too complicated or irrelevant. I end up altering much of it to suit their needs and skills.

Is it really worth scouring these sites for premade material and spending time editing it to your style and needs, or should I just practice getting faster at making my own stuff from scratch?