If you’re purchasing quality sweaters and rotating them properly they won’t need much cleaning.
The best advice is follow instructions on your care tag.
Rinse gently with cold water and squeeze the garment but do not ring it.
Twisting the garment will destroy the fibers and the sweater will never be the same.
Instead, squeeze out the water and soap gently and reshape it to its natural form.
Lay it flat on a dry towel and pay it dry with another.
Then let nature take over the drying process.
This is better than dumping it in the washer and dryer, but it will prevent shrinking, and destroying the fibers.