Tried the yellow card in the right shorts pocket yesterday.
I liked it.
Had an incident where two players got up pushing and shoving following a reckless tackle. Reached immediately into my right pocket, pulled out the yellow card, held it down as I jogged over to the two players, they saw me coming with the card in my hand (held down) and straight away they stopped their bickering. I then raised the card to the player who committed the reckless tackle. Worked a treat.
Oh yes, the spare set. It is a good idea to ahve the spare set in the top pocket. Good idea.
Nothing worse than dropping your caution card somehow and then being stuck having to ask the player for it back who is running around the field showing it to everyone having a great laugh!!! I had that happen once.
A good idea for the assistant referees to also have a set each as well just in case so they can help the ref out if there is a need of a spare.
YC in left short pocket - Double yellows are quicker and easier as I issue caution with left and send off with right. No getting one card out and then putting it back and getting the next out then. RC in back pocket - allows time to think am I 100% sure I am correct. Notebook in Shirt (I also use write on cards so this is just in case I want longer notes on an incident). Agree spare cards are good idea.
I have tried keeping the yellow and red cards seperate on a few occasions. But invariably I go back the keeping both in the wallet in my top left shirt pocket. I have NEVER pulled the wrong card out because I can see both when I get the wallet out.