I only keep as much line on my apron as I will use. But, sometimes all of it is sitting on your apron. I've had my share of tangles to the point I just deal with it as a fact of fly fishing.

One thing I will do is stretch my line a little when I first start stripping out my line. Sometimes the memory in the line will encourage tangles. Even so, tangles happen. I just hope a big fish doesn't take my fly while I untangle my line.