Keep it simple and easy for crowd to repeat. If you use signs make sure you show them before you expect the crowd to say them. I highly suggest watching some of the College and High School videos from UCA to get an idea. Also if you are using signs, make sure either the whole word is on one sign, or each letter is on a sign. No weird splits like BUL-LD-OGS. At coach clinics they have mentioned how much they hate that. If you aren't spelling out the mascot in the cheer then use signs with the word all on one sign.
Also when I say simple I mean simple, "Yell it Black-Black, Yell it White-White, Yell it Gold, Gold" *repeat* Then "all together, all together yell it black white and gold, black white and gold, black white and gold, black white and gold". "Let's go Bulldogs, yell with us let's go bulldogs, let's go bulldogs, let's go bulldogs".
If it's too involved the crowd won't know what or when to yell.