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Miniature animal or action figurines.
An orange.It works for Christmas stockings, so why not Easter?
Goldfish or bunny crackers.
Fruit gummies or fruit rolls.
Playing cards.Besides the standard packs, consider Go Fish, Skipbo, Monopoly Deal, or Phase 10. My family loves all these games.
Stuffed animal or doll.
Nail polish.(Piggy Paint is a non-toxic version to try.)
Marbles.(Only past the mouthing stage.)
Toothbrush.Electric ones are fun.
Undies and socks.
$2 bill or $1 coin or foreign coins.(Obviously, this depends on what is novel in your country. Money in general also works.)
Hat.A fetching bonnet for spring, perhaps?
Origami paper + instruction book.
Magazine subscription.Highlights has fun ones for babies on up. I love that Hello for ages 0-2 is sturdy enough not to dissolve in drool, and and they have other options for preschoolers and grade school kids.
Dice or tile games.Tenzi's easy and comes in bright colors. Bananagrams and Story Cubes are fun for language lovers.
Fabric and/or sewing kit.Preschool-age kids will just like to play with whatever materials you give them (fabric, glue, sequins, scissors). For elementary age on up, consider buying an easy-sew pattern, such as a tote bag, pillowcase, or pajama pants, and bundling it with the fabric and notions necessary to put it all together.
Magic pen book.These things still do seem like magic to me.
Construction kit.Build something together.
Little notebook or diary.Kids, even young ones, love having their own private place to scribble, oftentimes literally.
Mad Libs.Always funny. Especially if you favor potty humor the way we do.
Plants.Tiny succulents are on trend and could please a budding green thumb. I also both adored and feared a mini-cactus I had as a child. Since either doesn't take much watering, these choices would be appropriate training for a young plant tender. If you have an actual garden outdoors, a seedling kit (mini pot + seed-starting soil + seeds) that can be transferred later in the spring would be fun to tend — strawberries, tomatoes, herbs, or whatever your kiddo will want to eat when it's grown.
Craft supplies.Stickers in particular are always a hit, but new markers or glitter glue or washi tape or rubber stamps or the like would be welcome.
Office supplies.I might be alone here, but I suspect not. My eight-year-old loves tape of any kind, staplers and staples, hole punches, new pencils and pens (extra credit if they're in interesting inks or colors), Post-It notes, and similar goodies. These are all usable in multiple applications far beyond Easter morning.
Hardboiled dyed eggsOf course!
Ideas for the bucket and stuffing:
For buckets, I love to choose something practical and reusable. If you have room to store dedicated Easter baskets, remember where you put them, and get them out each year (go, you!), don't let me stop you. But, since we live near a beach, one of my favorites is to use a new beach bucket that can be repurposed for sandy play. (This idea works equally well if you live near a sandbox or a source of water. Buckets! They're awesome!)
Other ideas include a gift bag, a pretty drawstring cloth bag, a tote bag, a cute purse, a backpack, child-size watering can, or baskets you source from the thrift shop or yard sales. You could also skip the bag and wrap everything in paper or cloth. Kids love unwrapping surprises!
For filler in place of plastic grass, consider new Easter clothing, a t-shirt or other special new clothes, shredded colorful recycled paper (you could use magazines for this), living wheatgrass (use it for smoothies or give it to your kitties afterward), pretty fabric for a sewing project, new doll clothes, or dress-up clothes. Or, you know, you could skip the "grass" — little kids in particular aren't going to notice or care.
Leave your own tips for a natural-minded Easter in the comments.