Glue the centre section struts to the fuselage at the correct angle and let these mostly set, before proceeding. It can be helpful to use lego bricks and plasticene or Blu-Tac to make a little jig to hold these in the correct position while setting.
Use a pair of dividers to check that the gap between the struts is exactly the same distance as the locating holes in the top wing. When these struts are reasonably firm, glue the top wing on top. If there is a lot of stagger between the wings you probably need to position the plane over a plan and maybe use a set-square to check the stagger is right.
Don't worry about the interplane struts at this stage. It is a lot easier to manage four struts at this stage than 8, 12 or 16. While the top wing is drying check that the wing leading edges are parallel.
When the top wing is dry you can insert & glue the interplane struts.
Works OK for me. Still stressful though
