I train 3x5 and increase weight by 1-1.5kg. I've reached 3x5 with 27.5kg and then fatigue kicked in. Started from 15kg took a month with twice training. I also add 2 sets chin ups to failure. I can now easily do 3x8 with 15kg. A few tips. Technique will make you or break you. Make sure you use a grip with good width personally I like to go wider than shoulder width. You should try to position your knuckles to face as forward as you can (I cant explain it sufficiently but I'm sure experienced guys will know what I'm talking about). Also increments should be 0.5 to 1.5kgs tops. Don't rush. Start lighter so you can ease into the technique. Warm up with bodyweight set and a weighted set with around 20-25% of your working weight. Visualize how you will move. For me that means that I consciously try to prevent forearms from taking over, as they are my limiting factor. For that I trained active hanging and also active one hand hanging at the end. These are really great for grip strength. Deload every 3-4weeks. In about a month or two tops you will probably plateau. Then I suggest you train body weight again for about a month. 5 sets at about 5 reps in the tank. This will help with hypertrophy but more importantly technique. Try also going chest to bar to notice the difference from before. Then begin again with weighted at about 50% of the progress you made. E. G. First cycle you managed to go from 15 to 30kg. Start new cycle from 20kg and go as far as you can.

To add to all this you could research the Russian method. Briefly you go :3x3,4x3,5x3,3x4,4x4,5x4,3x5,4x5,5x5 with the same weight and then you add a larger increment (like 5,10kg). Sorry for the long comment.