Are you using a template follower, with the router mouted in a table,
or are you hand routing from above? If you are hand routing from
above, go clockwise on exterior cuts, and counter clockwise on pockets
and interior holes, this is will cause the cuting edge to rotate into
the material. Going the opposite direction will cause the cutting edge
to lift material out of the cut, thus causing tear-out. You may also
notice that the router tries to move away from the template, I usually
make serveral passes to insure that I have routed flush to the
template. Long grain woods like oak are notorious for tear out so keep
at it, and you will get their with practice.
Is there a way to clamp a sacrificial piece of wood next to where the
cut exits? Using a backer block can eliminate a lot of tear out.