I make sure I get to work a good 15 minutes earlier, so I have time to change if needed, and freshen up, and calm down too, if the commute got me working out.
I most often will wear, under my work clothes, a layer that will sort of 'soak up' any sweat, a layer that I can take off once at work. As for my commute back, I don't worry about it since I am getting back home, so getting there sweaty is not a problem.
That layer will often consist of biking undergarments (biking underwear from Juniona and a simple cotton tee).
I hope this helps.