By DH106
 

... one. This will cause the concerned part to only use half the original complexity - used on a whole creation, this helps a lot. Only do this though when You no longer want to tweak the part; after this treatment editing is a bit harder.

By DH106
 

Another little thing: If You like to gain a serious amount of free complexity, also use asymmetry on symmetric parts. Those fuselage parts all consist of two identical elements originally; by holding down A and clicking them You can remove the second...

By DH106
 

Thank You for all Your comments - and I am glad You like my little alterations to Your design.