It is a sad truth that much of boat building is sanding (a term from last century as we are now using glass, aluminium oxide etc).
Whether it is 50, 60 or 70 percent of the build it needs avoiding like the plague. So using peel ply and being as neat and tidy as you can is a start. Using masking tape when filleting and cleaning up when the epoxy is green all go a long way.
Once it’s set and before you reach for sand paper try a scraper these can remove material much easier and locally.
I never use electrical machines, mainly because my boat building is done before the sun has broken the horizon and the family is still in the land of nod. I use a good sanding block with good paper and find it is far more efficient. Sanding blocks also stop you locally creating dips and give a fairer finish.
It will depend on what you’re sanding but keeping the paper fresh saves time. With a few passes you will have created dust and frequently removing the dust is critical other wise you’re just sanding dust.
Eventually the paper will clog but it is far from dead, a brisk rub with a small wire brush and it’s good again.
The next thought is not stopping too quickly, sanding is tedious and it’s easy to get bored and add more filler (weight) and time to the build.
Reading what you have sanded is best done by feeling, the tips fingers will detect the slightest flaw but got lighting is critical to get the bigger picture.