One of the big planning items in kit building is figuring out when to paint each part. The two extremes are assembling the whole kit first and then painting, or painting each part before assembly. Normally the ideal is somewhere in between, which I characterize as paint a little, assemble a little, repeat.... Painting each part and then assembling tends to leave visible seams where there shouldn't be any, but assembling completely and then painting risks finding areas that you cannot paint.
Now, each kit is different- you need to look at the assembly instructions and figure out when you paint what, trying to avoid the two problems. It would be nice if kit mfgrs did a better job in helping with this, but most do not. In fact, I figure most kit mfgrs figure very few modelers ever paint their kits :-(
Often on high wing strut braced aircraft, I leave the struts off until after painting the major structure, painting struts, landing gear, etc. seperately and adding them after the major airframe assembly is painted.