Always start out with soaking/dripping warm/hot water on soft cloth (microfiber) (a drop or two of soft soap is OK, but not necessary. Preferably as soon as you get home. The longer they are on, the harder you have to work, and the more risk of scratching from pushing (shield or whole bike). Bug guts are acid, and eat paint with time. Any grit or sand on your cleaning rags is bad. Using (expensive) polishes on bugs is a waste of product, and just smears them around.
Some are using hydrogen peroxide, which is very cheap.
Once the worst is off, then clean with whatever you use (not windex, ammonia, bleach), I use (no abrasive) plastic polish.
I use this

But because the pump just sprays everywhere wastefully, I pour it into used eyeglass cleaner atomizers which put out a fine mist which is all you need. Does the whole bike nicely with microfiber. Just one small atomizer will serve for weeks and weeks.
