You can get more of a grip focus out of your dead lift workouts by using fewer fingers to hold the bar. For example do your first warm up set using just your index and middle fingers. Add more weight and use your index, middle and ring fingers. Next you can use a thumbless or false grip. Finally wrap your thumbs around the bar for your heaviest sets.
If you get creative you can use this technique on lots of pulling exercises. Climbers do all kinds of chin ups, even with just 1 finger. Start easy, and progress slowly and steadily. Finger lifts can hurt at first so ease into them.
As far as a workout, you could do something like;
Deadlift, add a few sets to stress the grip
plate pinch hold, light weight long hold
reverse dumbbell curls, high reps
a couple days later try
Hammer Curls, sets of 8, start light add weight and do sets till its hard to get 8
Dumbell Farmer’s Walk, start light, pick a distance and keeping adding weight till that distance is tough
Wrist Roller, start light roll forward and back, thats 1 “set.” Add weight till its difficult.
when you feel ready
Plate Pinch hold, heavy weight for short time. If you can’t hold at least 25’s with 1 hand, use both hands.
Reverse curls, medium weight medium reps
Barbell wrist curls, standing with the barbell behind your back, reps till failure
another one could be
Shruggs with dumbbells, reps till grip gives out
wrist roller for a few light sets.
as far as progression, pick an exercise. Go heavy for low reps or short time for your first exercise of your grip workout when your fresh. 2nd exercise should be moderate weight for more reps or longer time than the 1st lift. 3rd exercise is like a pump till failure lift.
Start really light and really easy and add weight for 4-5 sets until you get to a difficult but do able set. Next time you do that exercise, maybe 5 days or a week later, warm up and do 2 work sets with the whatever was difficult but do-able last week. Then, just kind of add weight or time/reps as you get stronger. Don’t worry about “percentages” just do what you can handle. The lighter and easier you start the longer you can make steady progress with no injuries.