We are lucky that we live at the beach. A giant expanse of sand and water makes for a fun day no matter how old you are. For my son (who turned 12 today), digging holes in the sand, throwing sand bombs at his friends, and boogie boarding all day long are the keys to a great time. Therefore, planning the venue and activities for a great day are easy: take the above ingredients, add a bunch of boys and snacks, then mix well.
Now... how to make it thrifty? First of all, everyone brings his own sack lunch. That way every kid gets what he likes. I decided to provide snacks and beverages for the tribe. Big Lots had cases of 24 water bottles for around $4/each, so I bought two. Stater Brothers had powdered drink mix on sale, so I bought two. Hubby bought one Kool-Aid, which was slightly more expensive, but it did taste better. I made "tropical punch", grape and lemonade flavored water, then froze them. Now there are frosty beverages available to the boys all day. I did keep about half a case of water plain, for the purists. I'll just keep them in the cooler all day and let them melt naturally. We can mark the caps with a Sharpie for boys who want to sip/suck on their icy bottle and save it for later.
Snacks... boys will eat just about anything (at least the ones I know will), so Big Lots came through for us again. We bought individually wrapped Cheetohs, Moon Pies and Froot-by-the-Foot, all at discount prices. Those will be available for eating all day.
Every good birthday party has a main activity and/or goodie bag. These boys are all getting a little old for traditional goodie bags (at a recent toddler party we attended the mother gave my boys "older boy" goodie bags with good intentions; they donated all the items to charity). Instead, we hit Lowe's and Wal-Mart for heavy-duty outdoor shovels which the boys can use to dig a good-sized trench (or two) at the beach, then use them later in their back yards to do some heavy duty earth-turning. We love our industrial shovels and they're not that expensive. A long-handled metal shovel at Wal-Mart was less than $5, making it very affordable for a give-away.
Every boy will bring his own towel and boogie board, so we're covered there, as well. We're looking forward to a great day at the beach celebrating Steve's birthday!