I've made several of the flag inlay kits. Here's what works for me.
Put the tube into the blank for support while working. I use tweezers and my head magnifiers. I put a few drops of liquid dishwashing soap in a small bowl of water and mix. I then briefly dip the star I'm placing into the soapy water prior to placing it into it's hole on the blank. I push it in with the tweezers enough to get it started and oriented in the correct position. I then use a small tube (the plastic handle from detail paint brush), which I roll over the star several times using pressure. This seats the star all the way into the hole. I can verify that it's seated all the way by pulling out the brass tube and looking at the inside of the blank if I need to, but after you've done several you get a feel for what's fully seated. This varies by the kit since some of the pieces seem to be cut thicker on certain kits, but is uniform for the entire kit.
Once all the pieces are fully seated, I let the blank dry overnight, then flood the inside and outside of the blank with thin CA to fix everything in place (be sure you wear vinyl gloves for this DAMHIKT). This invariably makes the blank hole too small for the brass tube, so I redrill the hole with the correct drill size. For the flag kits, I square up the ends of the stars and the stripes blanks before epoxying them together and to the tube so they form a seamless joint at the right spot. Of course you have to cut the ends off the stripes blank after it's been CA'd. I usually cut just beyond the stripes then sand the rest of the way on my disc sander.
