Just laced up my first wheel today.... satisfying, easy'ish... and likely saved £300 I guess. The actual lacing / tru'ing probably took a little over 2 hours. But... the next will be quicker!
Not presenting this as 'the only way to do it'... but it worked for me.
(1) Get hold of a solid / flat piece of wood, 22"x22" minimum.... an old kitchen unit door?
(2) drill an 1/8" hole in its centre.
(3) Scribe a circle onto the wood the exact outside diameter of your new rim. I used a hack-saw blade drilled out at the appropriate average radius of my DSS DID rim.
(4) Open up the centre hole (using a suitable hole saw) above so that the hub 'boss' drops in @ a snug fit... no play allowed. (Or any suitable method to 'clamp' your hub to the centre of the scribed circle)
(5) Insert all spokes into the hub and loosely lace up the wheel using the other Wheel as a reference. (or good photos). Only put 3 or 4 turns on each nipple. Use both the flat wood & stand the wheel up for this... whatever suits. (insert spokes from the outside in & lace these up first, and then insert the other 1/2 of spokes from the inside-out & lace up)
(6) With the rim now sloppily laced to the hub lay the whole lot into the wood 'jig'.
(7) Place 'spacers' under the rim to raise it to the correct height to the hub. (For some reason this pic is upside down until opened up!)
(

Manoeuvre the rim to sit as exactly as possible within the scribed circle... there will be a fair amount of leeway at the point.
(9) Now finger tighten / nip up all the nipples. The hard yards are done: the rim should be both laterally & radially pretty much 'there'.
(10) Assemble the hub completely, and mount onto the bike.
(11) Grab a cuppa tea, put radio on, lie next to the bike and stick a strip of masking tape across any two points... I used the front stays in the below pic. (... and this pic is on its side!)
(12) Radial adjustment (making it circular). Spin the wheel slowly... and tighten / loosen spoke nipples accordingly. Move the tape as you really get the tolerances down. You're aiming for abouts 0.03" or just <1mm. Doable... with a bit of patience
(13) Axial play... on the tape draw vertical 'boundary' lines to coincide with the rim width. Adjust the nipples (ie tighten one side / loosen the other) to pull the rim to one side or the other. Again, not as difficult as you'd imagine.
(14) spin the wheel more & recheck that radial play / adjust if necessary.
(15) ditto axial play.
(16) Just about done...ping all spokes with a screwdriver and check all give a nice ring. Any dull 'thunks' and that spoke needs tightening up. (and possibly a recheck of radial / axial plays)
(17) Treat yourself to something with the £300 saved...