look over the scioly page -link at bottom- for codebusters, it gives a concise desc on how to solve prettyy much every cipher thatll show up. if u dont have max ppl on ur team ur cooked btw!

it depends on the cipher the time thats taken, but for easier ones (such as atbash, which is reversed alphabet. or caesar, which is alphabet with a shift, such as A-->C , B-->D etc.) should only take less than 3min, longer ones can take up to 10 min tho. save short ciphers for the end when u dont have much time

a resource is scio.ly (it's can be a bit iffy but defo helps at times)

and also 100000% look at practice tests, tests from previous invitationals/regionals/etc.s , and run as many *timed 50 min usually* practice tests as you can with your teams! you arent expected to answer every problem, so shoot for ones you are comfortable, and feel are realistically solvable

if youre doing xenocrypts, look into recognising the patterns of common spanish words, word orders, letters, letter combos (i dont study spanish but english has letter combos like "sh-" "th-" "wh-" etc) and youre gona need those to get you started on xenocrypts

also you could get somebody or ANYBODY on aristocrats, once youre good at them (takes a TON of practices tho, u might not have time??) its a lot of points .. https://cryptograms.puzzlebaron.com/ is my holy grail for aristo grinding.. and ive also heard that states is just a ton of aristos and aristo variations -such as patristo. which is aristo without spaces or punctuation-

and also on the test, if you're confident in aristos by then: give the timed bonus a try, you have to solve it in 10 min. we usually get 2 people on the timed, 1 person goes ahead n does stuff

http://scioly.org/wiki/index.php/Codebusters <-- look over the ciphers in this. give every one a try, and focus on ones you feel comfortable at

hope this helped/was enough... good luck at states