Slightly off topic, but what bikes are you all using? I ask this as a Dutch person who has been cycling a lengthy commute (30 mins at the least) from the age of 11/12 onward and the only time I've ever had sweat issues was in my teenage days when I was running late and going at really high speeds on a bike with teeny tiny wheels. Even then it wasn't enough to warrant anything other than a quick spray of deodorant. Don't know of anyone else who is encumbered by it to affect their clothing choices either, unless they have a race bike and ride for sport.
Our biking woes generally come down to ho to recover when you look like a drowned rat after being caught in some unexpected rain and where to find a jacket that doesn't catch on the saddle at the back all the time.
General hacks from here are, never layer up too much under your coat in winter to avoid boiling, relying on gloves, scarfs, hats, and the actual activity of cycling to keep you warm. A newspaper on your chest (under your coat/shirt) if there's cold penetrating winds (be careful about ink though) is an old trick that's really effective. Elastics round the hems of your pants to keep wind out.
I have a crate at the front end to carry whatever bag and/or groceries, people usually have one of those, a basket, or the attached double cycle bags at the back, personally have never had a sweaty back from a backpack either.
Skirts are fine to wear, even in summer, you don't really see anything, unless you wear really colourful underwear with an especially short skirt, provided your saddle is at the right height. Wider skirts with a tendency to catch the wind and reveal all can be knotted up with an elastic as mentioned above.