Wooo is doing the the old Rest-Pause system, which I highly endorse (for whatever value that may have..do what you wish). The usually pause between reps is 10 to 12 seconds, sometimes 15 seconds but never more. Written about my use (and others) of R-P for quite a while now.
For the average trainee; if using 225 for shrugs, say for 10 reps for regular sets, with the Rest-Pause system one could be using around 250+ for those 10 reps. Allowing that 10 to 12 second pause between each rep. Tend to gain strength very fast with this method. The next shrug workout might find the reps going up to 14 to 15 easily. This method works well with benches, DL's, etc.. BB curls adapt well with this system.
Straps will allow that extra demand on the muscles being worked. If doing DL's, shrugs, rows, etc and the grip gives out at 5 reps without straps,and you know your good for another 2 to 3 reps, this is where straps become the most useful, allowing the full potential of getting the most from a set. Works well with weighted chins also. Don't want to depend on straps all the time, the grip needs heavier resistance, but for the last set(s) where the poundage is the greatest..by all means.And the grip tends to catch up to the heavier weight. I prefer the nylon ones (told the basic same material as seat/airline belts. Cotton ones (like martial arts belt material) tend to snap/tear when you need them the most.
Straps also work well when doing the overload principle, with regards to any type of pulls.. Where the ligaments and tendons can be strengthen through heavier work. Even standing, while holding a heavier load than what the body is accustomed to, increases the ligament/tendon and muscle strength. If doing 500 for a one rep DL ,try adding a 100 lbs, taking it from a PR and just holding for 10 seconds. Shrugs should also go up with this method. As do 3 to 4 inch lockouts when doing benches and other pushing movements.
Some guys will alternate the over/under grip when doing shrug, though mostly for DL's. Over/unders insure a better grip and rolling out of the bar without straps. If doing the Jefferson lift (another great overlooked exercise) than a alternate grip is required each set or
workout.
The above is for BB'ing purposes. Serious PL'ers and Olympic lifters training methods may be different. Good Luck.