This is the order I rig... (hope i haven't forgot anything..easier for me to do than to type up)
This way it's quick and keeps the chasing things to one or two adjustments usually, and you are Done...(unless its really bent, but this will average that out also...)
Basically do what the books says, with a few extra checks/averages....
FIRST! make sure.. or at least an attempt at the bottoms of flaps and ailerons being level with bottom of wing using a strait edge...... don't care if the ends don't line up on side of fuselage or tip, we only care how it will fly.( they will line up if the tip and fuselage gingerbread are in right place)
Set fin so if you were to look forward at where top of it points, it would end about 1 inch to left wing side of center skylight Chanel at front spar.
Do the string and get the dihedral height right...
Set up plane to approx level flight for now..
**Then use level on fuselage side to side..find happy medium, across: spar attach points, gear fittings, engine mount studs.. sometimes you need to look behind gear area to find a untweaked area.... just find what you will now on call level, it may have to be an average... and adjust plane to it..
**This is now where you note how much T&B bubble is off... write this down... half bubble to the left or whatever... you could set plane down and adjust this now, but I wait till I have the plane down for another step.....
Now use the level at about strut attach area on leading edge bottom..... set plane down, turn one front strut in same amount as you turn other front strut out to make level read same amount off level on each wing..
**Now to set plane up in level flight, I use 1 degree trailing edge down at root rib(which I got off a virgin piper fuselage), check both root ribs, and split the difference. there are other thoughts on where level is..... but this has always worked great....my $0.02....... note. Univair rear PA-18 spars have wing attach holes about an eighth inch to high or low...cant remember which...
Check twist with the 3/8" block and adjust with rear struts as needed...
.....
As for what to fix/chase FIRST after test flights, we know the ball is telling the truth now, so adjust fin to make it right( use top wire to move tail post some, bend fin some also)
only concern yourself with which wing is heavy when ball is centered... (by foot pressure or rigged right), for rigging we don't care what it does when the ball is not centered....
**Sometimes its nice..or scary to measure from rear strut attach bolt ends on wing to the tail spring mount bolt to see how crooked wings are on plane, bent, or trammed wrong, if you are still having trouble..... have seen 5" & 6" difference side to side on a few flying planes.... but it does make the rigging rules kinda moot making one of these behave... a little over 1" is about normal... have only seen 1 plane in almost 20 years with no difference....