How to avoid showering twice when cycling to and from work?
Very good antiperspirant for the morning ride can work, dressing as cool as possible and changing clothes when you get in. Everyone has an upper limit for effort/distance/temperature for which this works, and if you work at the top of a hill, forget it. 

Slowing down for the last bit can help. You may even be able to take your helmet off for the last couple of hundred metres. This can make a big difference but only you can judge the riding conditions. 

I didn't find that baby wipes made for a good freshen up.