Choosing a pattern size

I was wondering if anyone out there cuts a pattern based on finished garment size v. the body measurement size?

I am usually between sizes and end up cutting the larger size when making a muslin. I'm wondering if I select a size based on finished size, the muslin will require less alteration. Let me know what your experience is with this!

HI There!
I am a professional seamstress and I give this piece of advice to everyone who asks this question...always open the pattern and check the finished measurement size in the area of the pattern is question.  If you are making a top, for example, the bust measurement would be the one to check. 
I always use this method when purchasing a pattern.  That being said, however, sometimes you still have to alter for an exact fit, that's just the way it is, but I find this keeps the precise altering to a minimum. 
Hope this helps! 

Thank you! I'm still a bit new to sewing, so I wasn't sure. So many patterns have so much ease, that it didn't make sense to me to use body measurements.