Free: Contests & Raffles.
Know county/local laws too. Depending on how close the neighbors build a 'structure' to your property line, it may remove parts of your land from being huntable. Example--some counties i think it is 'no discharge' within 150 ft of a 'structure', so if the nieghbor has a barn/shed/pumphouse by the property line, it can take out a good sized portion.
Try to get 5 acres adjacent to public land or private timberland that is open to hunting.