Glue.

Mine is a simple square of old construction ply.
Around the top flat side edges are strips of 2 core house electrical cord stapled on.. this holds the trace off the board and makes putting traces on and off easier.
 The edges have knicks cut in with the bandsaw to hold the traces... traces lay in 2 directions 12 one way 13 the other.
 A couple 50mm x 50mm across the back of the board has it sit up off the hooks and clips...and stops the ply from warping... if warps
 To tie traces to correct length and tension..
Snell the hook...put it in the knick, measure of the trace to wher the knot will sit on the other side... put a little fold in that place....the knot polmar.
Doubled over at the 'fold, thru the clip eye, 1/2 hitch it, loop the fold over the clip, hold the fold on the clip eye, pull up tight.
 The amount of trace used in the knot gives good and consistent tension.

This is mine when used a extension lead reel for back bone.. the reel floats weight all sat in the container.

 It stood up well for over 5yrs now.. have a reel that drops into a seat pedistle, no need for container , container replaced by 2 50x50 bits wood last week.. as mentioned above.

PS to keep hooks in good condition longer espec when not used for months on end.. wash wit boat/ rods etc...light spray with lanolin couple times a yr.