Rather than zip ties, I usu tape the spokes at the third cross.
jdawginsc , centering the rim isn't a big deal. I use a centering gauge I bought decades ago, but RJ has a simple trick using two stacks of books (or whatever). You set the wheel on one side of the rim on the two stacks, then slide some spacer (another book, for example) under the axle in between. Get a sense of the distance from the axle to the spacer, then flip the wheel over. If there's a difference, loosen one side and tighten the other to compensate. Lather rinse repeat. At that point, it becomes a three-way dance between lateral true, radial true and centering. RJ's video will explain it better than anything written.