OK, I've heard it both ways- for easy maintenance -

A. Have beds meet hardscape and lawn at right angles because a narrow point is hard to keep up.

B. Avoid right angles because they are hard to mow. (My DH belongs to this school- but I'm the one trying to keep the beds neat.)

Also, I've never had a riding mower- what kind of turning radius would the average homeowner model have? I'm trying to avoid too tight a curve/ too small a space for a riding mower. I know the newer ones can almost turn on a dime.

Maybe I ought to include a question about this when I talk to the clients. Riding or push? I do find out if they hire lawn care.