So it's different everywhere.. In my school some of us wore body liners and some of us wore tank-tops and mini shorts to practice I personally wear tank-top and shorts but do what ever everyone else does:) it's different everywhere!
You require considering change of climate for you to be able to wear the body liner for practice. As fall season hits, this is the perfect season for you to spice up things by mix and matching. This is also the appropriate time to wear your bodyliners. Read http://varsitysideline.com/tag/cheerleading-uniforms.