I never wash sheets and towels / heavy-terry-cotton items together, whether toploader or frontloader. Too much disparity in the saturated weight of the items for the machine to balance for spin, and towels can get caught in the pockets of the fitted sheets which prevents them from separating during distribution for the balance routine.

I may occasionally wash sheets and casual shirts together, as the fabric weight is much similar.

All white/cotton items (bath towels & washcloths, kitchen towels & dishcloths, socks) go together, including some pastel/color towels that can take the occasional chlorine bleach treatment.

The few dark-colored bath towels (that don't bleed) go with dark (navy, tan, khaki, etc.) casual shorts (and slacks, which are rare here, LOL). This also typically includes underwear which are fashion-color briefs.

Jeans are separate from anything else, although dark chocolate hand towels and a dark green bath towel may be included.