Like American Kenpo, World Modern Arnis has its own etiquette rules. A very practical rule is "Never pick up another person's stick or weapon". The reason is simple: if you pick up your opponent's stick in a fight, he may take advantage of you, and attack while you are being courteous. Or if a street fight has just concluded, and you are the victor, you don't want to be found with a weapon in your hand when the police arrive. They conclude incorrectly that you used "unreasonable force" (you used a weapon while your opponent had no weapon).
In our dojo, when you drop a stick or any other weapon, by the same rule, you alone pick it up. Before you do, your reward for being careless is 10 push-ups, and it doesn't matter what rank you possess (Datu Tim and the sensei may be exempted, but I have yet to see Datu drop a stick EVER).
When you are not working on a weapon's drill, the stick must be secured. If you don't want to hold it, place it behind your back beneath your belt so that you can draw it when you need it and it does not interfere with your arms and legs. If it were a real weapon, like a sword or knife, it would have a sheath or belt hanger. If you are working with a stick, and your instructor calls attention, hold the stick with both hands in front of you with your feet together.
As in Kenpo, each form in Arnis begins from an attention stance, followed by a salutation, and a return to the attention stance. The salutation is different for each martial art, and the video below features Sensei Carl Outram demonstrating and explaining the Arnis salutation.