I am a K track man for all my Marklin life. My usual “method” of track laying is to use an MDF board with floor underlay as a track bed and with the track screwed down in as few places as practical to leave it secure and firm. Wiring disappears below the board through 5mm drilled holes. Now I am going to try a small C track project – a very modest shunting frame.
So – C track? The same MDF board – no track bed. I presume the wiring is carried under the track and drill holes made to take it below the board. I will be using turnouts with 74491 motors to be wired to a 60831 decoder along with a couple of uncouplers as well. So what is the best practice for securing the track to the board – I have a box of C track screws. Is it the same - as few a possible leaving the track secure? Any other little tips would be helpful to a C track newbe.

I use the C track screws, but I do not use all the holes for the screws. I use what ever amount is needed for the track to be secure.

I have also used MDF underneath the track, it works just fine and I drill holes in the MDF to feed the track every 1 - 1.5 meter. I usually create a larger hole underneath turnouts to be able to service the turnout motors. This has been helpful through the years when a motor stops working.

Another option is to build the way Märklin of Sweden did with his M-track - he doesn't secure the M-track to the base, he glues down foam-core board bevel cut to lock the track in place (and there is padding between track and board base). This makes it easier to remove track pieces, but requires gluing down that clamping foam core board. Just an alternative approach.