Effect of 在 and 着 on verbs. What are the best single word translations?
The nuance between "在穿" and "穿着" is that the former emphasizes on my action and the latter on my status with clothing.

So "在穿" is associated with time. 
- "可以走了吗？"            Are we ready to go now?
- "等一下，我还在穿衣服"     One sec, I am still putting clothing on.

While "穿着" indicates the status quo of with clothing on
- 不懂为啥会着凉，我明明穿着很厚的衣服   Not quite sure why I got cold, I got lots of clothing on.

Also, baware of "穿着" indicates dress code as well, and 着 is pronounced as zhuo / 2nd tone rather than zhe.