Competition is keen for professional positions so all the OJT possible will benefit. Fire fighting is a common summer job but will not prepare you as a forester. Go to work for a timber company or governmental agency. Beef up oral and written communicative skills. Foresters have lots of contact with the public and do a lot of reports.
Governmental agencies require lots of documentation.
You are often called on to do expert testimony as well. The Society of American Foresters webpage. Just career exploration.