Once you’ve mastered the type writers (see blog #1&2) a rope with three knots in it comes in handy. When you can do at least 6 solid pull ups on both sides on the 1st knot move down to the 2nd knot and so on. By the time you have got strong enough to do 6 each side on knot 3 your getting close!
Ensure this training is supplemented with LOTS of antagonistic training to avoid elbow injuries. Press ups and tricep dips are good if you have no props/weights. There are lots of great articles on antagonistic training on the internet so I won’t go into it.
Remember climbing is the best way to train for climbing this is just a challenge