Ethics

Set a good example for others. If you see garbage in the woods pick a little up each time you go out and bring it home to throw away. Leave things better than you found them. Always present yourself in a clean-cut courteous manner. Hunters do not need to have a "Bubba" image.

You are morally responsible for the recovery of any animal you shoot. Expend all possible effort in tracking a wounded deer. This may mean getting down on your hands and knees to find a "pin drop" of blood. Or it may mean getting a few of your buddies out with you to do a grid search for the animal. Propane or kerosene lanterns are essential if you are following a blood-trail at night. Always mark the last spot of blood found with a little piece of tissue and leave it as un-disturbed as possible - you may have to return to this spot and retrace your steps

Safety

When climbing up to your tree-stand and while sitting in it use a harness.  Keep minimum slack in your harness and wear it towards your armpits rather than your waist.  This will keep the distance you fall to a minimum and keep you right-side-up, maintaining consciousness.

If you are climbing a tree using limbs it may be impossible to climb with a harness.  In this case you should always maintain 3 points of contact with the tree at all times.  I prefer to maintain 4 when possible. 

Installing a portable tree stand can be one of the most dangerous hunting activities.  Make sure that you are always harnessed while doing so and try to take a buddy with you to hold a light, or otherwise give you a helping hand.

Always tell someone where you are going and when you will be back.  If you are overdue they can at least come to check on you.