So when restyling a jacket start with something that fits you reasonably well. Recutting an armhole or refashioning a shoulder is expensive and the results can be disappointing.

Changing a jacket or coat collar from a shape like Peter Pan, for example, to a smaller point collar can transform the look from retro to modern.  Remove a collar altogether for a clean, minimalist line.  Narrowing a too wide lapel to a current-looking width or shortening sleeves to a 3/4 length are common requests and will not cost a lot. I recently took a black tux style jacket from 3 years ago ( at least) to my tailor for a sleeve removal. He finished the armholes beautifully and suggested that he narrow the lapels - just a tick- for balance. The result is a new jacket/vest for under $75. 

Wide leg pants languishing in your closet? It is easy for a tailor to narrow the leg to an au courant stovepipe line. What about that poker straight skirt ( with the weird length)? Restyling a straight skirt to a pencil shape is easy. The success of the pencil is the subtle narrowing at the hem that gives it that essential curve.

A sack shape dress to a sheath?  In general, an easy fix.  An unheard of sale on designer jeans but the available sizes are too big? Go ahead. A tailor can style them to fit. 

Shopping your closet can be better than bargain hunting. Hit the attic. It could be a treasure hunt. If you don't have a good tailor it is time to find one.