Keef, as Pilot16 has an instructor he's probably not supposed to be using VOR/DME - it's supposed to be VFR nav at that stage
I'd only use a halfway waypoint, unless the leg was more than half an hour or so (i.e. 15 minutes to the waypoint), at which point i'd divide it up to roughly 15 minute legs. Obviously I'd use an easy to identify feature somewhere around halfway rather than an empty field at the exact halfway point!
The problem with too many waypoints is that theres more plogging to do and taken to an extreme (e.g. <10nm between waypoints) the examiner may be less than convinced about your VFR nav - you're really just feature-crawling. With a 15 min leg you're only going 20 miles or so, and even if you really b*gger up the heading (or fail to check the DI

) you aren't going to be so far from the waypoint that you cannot spot it - especially if you picked a good'un in the first place