Decal placement

Eyeball it. I usually use panel lines as starting points

Just keep that sucker lubed up with Micro-set (or which ever brand you like) so she moves around easy, use the ol' Mk. I eyeball, and look from every angle possible. Panel lines make good references.

I can usually eyeball it okay, but when there are few reference points on model I will use little pieces of low tack masking tape to create my own reference points. I can measure from a 3 view to find point to put tape.  I don't put the tape too close to where decal will go, maybe marks on top and bottom to put side decals on.

If you eyeball it , you will be ok.No one ever used overhead cranes to measure their paint jobs on aircraft.No judge in the whole modeling world has capability of doing that.Do your best and eyeball it .I did that , and now I have to many first place awards to prove that .Also I have sold many of my models w:the eyeball system.Do not get sucked in to the "" MR Perfect"" modeling system which does not exist .

Take my data.Because is is from an ex F-100 and F-100 Pilot .Histoian and modeler.

Well it seems that eyeballing is the consensus - which has failed me thus far but I have not used panel lines as reference. I like the low tack masking tape idea as well. Building a 1/144 A380 right now, will let you know how it turns out. Thanks for all the help guys.

Sorry I mentioned F-100 twice.Its the F-4c