Specialising in horn and string sections, I am composing & arranging for Moreland City Brass Band and have written charts for many other Latin, Rock, Soul, World Music bands.
I am quick. I can write out the rough draft of horn parts on an average Latin recording (often quite complicated) in an hour. Putting it on computer so that it is very readable and so you can print out the charts in a new key or for new instruments, takes pretty much another hour.
Composing parts / coming up with melodic horn ideas for your original tune is one of my fortes, but obviously takes longer than just writing out a recording.
I always choose the best options for readability, double bar lines to break up sections, and cues, no 39 bar rests to get lost in.
I am a professional Trumpet and Tenor Horn Player (Can play simpler French Horn and Trombone also) so if the chart is for a recording, I can play it with a full sounding brass section just on my own.