I'm looking to develop my triceps a little bit more and I would an advice on short training routine for v bar pushdowns, basically how many days a week, reps and sets, thank you.
I would say that there is no muscle needs to be trained more than twice per week. After all, you need to give them time for recovery, so training them more often won't allow for recovery. Also, there are a lot of different exercises you might want to do for the triceps, especially considering the fact that different exercises will train different parts of the triceps.
There is no need to train triceps more then 2x a week. Quality over quantity. Hit it hard and then let it rest and recover
There are two heads in the tricep. In order to work both heads, you need to do push down movements like rope cable pushdowns, also extension movements like overhead dumbbell tricep extensions.
Try a variety of different exercises and train your arms with multiple different rep ranges. Arms usually respond best to high rep training that really fills up the muscle with blood.
I would also include close grip bench press. The issue might be not enough food too. You can train all you want but if you aren't eating enough, you wont have muscle growth.