I generally use gel CA glue, which does not set up immediately- it takes a minute or two. I use it because the fit on plastic model kits is frequently not perfect, and the use of the gel means I don't have to file or sand each joint to fit perfectly. Second, it gives me some working time to get the angle/alignment perfect. So, I sympathize with the original post. Sometimes I set up a simple jig or support to hold the part in alignment. If I do not want to do that, I keep a bottle of CA accelerator handy, and have made an application tool for it. I put a big of gel CA on the part, or where it will go, set it down briefly, and load up my application tool with a drop of accelerator. Holding the part in place as best I can, I then touch my applicator tool to the joint, hardening the gel CA virtually intently.
My application tool is a large sewing needle stuck into a length of dowel ( point into the dowel, eye hanging out). Then, I grind off half the eye of the needle with a dremel and abrasive disk, leaving a fork, which holds a drop of accelerator.