When rigging those long skinny unstable loads like lumber and floor joists try and wrap a couple of nets around them to help break up some airflow then tie a tree off the end and from what I have seen usually the heavy end of the load will fly forward. The more stable you can get the load the less the work load and stress you will have especially on the longer flights.
I picked up a steel structure shed frame with an installed wood floor by a 4 point, 1800lbs and thought the tough part would be getting off the ground. So i waited until late in the evening when the temp cooled down. The load came off the ground ok then transiting forward it tilted back slightly with airspeed and acted like a spoiler. I Had a very tough time gaining altitude with all the drag of the floor surface area. So try to visualize how the load will fly to help with rigging but then again some loads you will never know and it can be hard to predict how they will fly.
Another trick in confined areas when having to hook up your own loads which some pilots may laugh at is to tie a piece of survey ribbon or make a marker so when verticaling down 100ft into a tight area with a lot of bush or snags around the tail area you can position the helicopter in the same position every time. Just make sure you also have a couple reference points out the front window to see exactly where the nose of the aircraft should be facing so you don't hit that tail. Then you can position the line wherever you need to then looking through the floor window position the aircraft into an area that you know is already safe. Have fun and fly safe.