A research study at the Medical University of South Carolina is looking at young adults' experiences with alcohol and e-cigarette use during a 4-week study. The study is enrolling adults ages 21 to 29 who use flavored ready-to-drink alcoholic beverages and e-cigarettes. Participants will complete in-person study visits, brief daily electronic diaries, questionnaires, and provide blood and urine samples for research testing. Some participants will be asked to avoid flavored ready-to-drink alcoholic beverages for 2 weeks, while others will continue their usual use. The purpose of the study is to learn whether this type of short-term study procedure is feasible and acceptable, and to better understand patterns of alcohol and e-cigarette use among young adults.