Don't just run in, approach slow and low to ensure that the mark is effective
One way to get more throwing (and less running) is for each thrower to have a set number of goes before rotating: 3-5 works well
A simple drill that gets people taking on a straight up mark and provides lots of repetitions in a short period of time
A handler, A, starts with the disc, marked by C. Another offensive player, B, starts 3-8m downfield of A.
Receiver > Thrower > Marker