Build a spool holder. A scrap of wood with a dowel spike sticking up, and an eyelet to run the wire through. And Actually, a stick from the yard and a couple of bent nails work better. You want some friction on the spool so it doesn't free wheel -- so rough construction is your friend.
Clear some workspace, clamp the spool holder at one end, and start your wiring at the far end. As you lead the wire, slide the frame toward the wire spool. Pull the half completed frame back to the far end and finish. Move the the frame through the wire instead of pulling the wire through the frame (as much as possible).
I tighten the wire by
1. wrapping nails on the side of the end bars -- the 5/8 brads go through the ears into the top and bottom bars reinforcing that joint from the side. When you nail off the brad to lock the wire, you tighten the tension a bit.
2. Wearing a lightweight workglove (cotton with rubber palms) to grip and pull with my "pulling hand".
3. *Important* I pull the wire on the endbars between holes off axis with a fingernail, and staple the wire with a 1/4" shop staple. You can take enormous slack off the wire by pulling it to the side. Stapling also means if you pop a wire, only one segment sags, not the whole network. You need a good eye to catch the wire just right with the staple, and you need a strong fingernail. Nail off the staple with a light tap.
4. I keep the wire from pulling into the frame wood by stapling below the wire to provide a rub point. Do this after glue is dry and before you begin the wiring process. Use 1/4 leg staples. All staples need to be nailed off with a tap. Figure your wire pattern and only staple on the side that needs it. They sell cute little brass eyelets for this purpose, but staples are cheaper and just as effective. If you don't staple off the guide, the wire will cut into the wood, become loose and sag.
Embed against a board -- cut loosely to the inner dimension of your frame. You can use a spur embedder warmed in a teapot. Knowing the temperature and pressure - not too much, not too hot -- is gained by experience. Embed from the top side- wire into the wax. *A thumb on a warm teaspoon* is a really good embedder. You use just enough pressure to push the wire into the wax, not cut the foundation below. The smooth even teaspoon doesnt tend to cut the wax the way the spur embedder does. I use a fine silver teaspoon inherrited from my great-great aunt -- makes me smile everytime I use it, but it shaped precisely to minimize wax damage.