1. tell someone where you are going to be and when if you are going alone...no matter how in shape you are you can break an ankle, especially if you are successful and find your pack is now 80 pounds heavier on the way out. have a contingency plan if you get injured...I have been unable to lighten my pack by taking out a personal location beacon
2. if you are in good shape, and don't break an ankle you will still need water....plan a way in and way out that has a water source you can filter / purify from....WA wilderness areas are pretty generous in this regard.
3. Scouting / gear test trips are a great idea...unfortunately I have wasted a lot of time futzin with my new gear when I could have been out glassing the hillsides...I am a newbie myself and have found that the less cool crap I have the more I learn about the wilderness around me and less about expensive gadgets that weigh my pack down....
good luck!