You can make a really nifty tub toy container with an old bleach bottle and a bit of coordination. The best thing about this, is you're helping the environment by reusing an old container and it's recyclable if it breaks.
Another favorite reusable item is the old onion or orange bag. I turn them into toy sacks. The bags relatively firm, convenient, can hang and do not hold water or sand. These are made of plastic so if they break you can recycle them. I love them because they were a quick and easy obvious option to hold water toys at first. The only setback is was that these bags can tear easily. Use them at the beach- they don't mold, they don't hold sand and you won't get mad if you lose them because they came free with your fruit. (Aside, don't lose them at the beach because you don't want to kill a seagull or fish)