Meow, Depending on what aspect of hooking you're looking to improve (scramming, line outs or the actual hook in the scrum) I would recommend looking at a range of work outs from things like over head tricep dips (1 dumbbell) to bent over rows (useful for retaining ball in rucks) to your basics such as squats, lunges and modifications of both to improve your general leg power in the scrum. If you're looking to focus more on your upper body for the line out side and rucking side of hooker I would go for exercises that place focus on your traps, upper back, biceps. This will increase your ability to retain ball and also improve your line outs.
