Between April 1 and May 20 save, earn, find $1 per day and you will have $50 (choose whatever dates you want to) - athletes can ask your friends, most will at least donate some change to a friend. Once they reach $50, go for a second $50 for yourself or to help a teammate
Your school huddle could collect change and bills from those attending huddle meetings to give to coaches and athletes at your school (make it a competition among freshmen, sophomores, juniors, seniors or girls vs guys)
Host a sports clinic at your school on a Saturday for 6-12 year olds and charge each participant, also be sure to share the gospel
Host a three-on-three basketball or volleyball tournament with entry fees for each team - could be adult or student tournament - share the gospel
Two or three families or a whole team could get together and have a garage sale
Sell some things on eBay
Make up a game - put different amounts on index cards (whatever amounts you want, $.50 to $5 or more, depending on whether its students or adults); ask the person if they would be willing to give to you the amount written on the card they choose; hold the cards out to them in a group and let them pick a card, then turn it over and they pay up the amount written.
Spaghetti lunch or dinner at your school or church - try to get noodles, sauce, meat, plates, etc. donated and ask senior adults in your church to make the desserts
Sell extra desserts at the spaghetti lunch or dinner
Powder Puff Football game
If you have someone in your area with a big grill and people to help, sell boxed chicken lunches to businesses in your community - go to the owners of businesses and ask if they would either buy the lunches for their employees or advertise it to their employees (this is a big project)
Ask local churches to have an FCA Day where athletes and coaches can share what God is doing through FCA on their campus and the church take up a love offering
Ask Rotary, Kiwanis, etc. in your community for the opportunity for athletes and coaches to speak and a donation be given
Athletes ask your neighbors if you can rake, mow and/or weed their yard, clean windows, etc.
Sunday school classes take up love offerings
Some local fast food and/or restaurants (Pizza Hut is one) will donate a percentage of the total bill your group spends when you eat there, have some great fellowship while eating and raising money at the same time. Encourage families from your school and church to participate to increase your earnings.
Ask your local radio station if they will allow you a day or two to share about FCA and ask their listeners to consider donating to camp scholarships