One of the things that boggles my mind each year is the sheer amount of candy tossed at our kiddos for each holiday, festivity, party, birthday, etc... I find myself having to horde it away and ration it out to keep her from eating it all in one sitting and giving herself a massive stomach ache. One of the traditions I wanted to start was having non-candy filler for Easter eggs (or just using real eggs most years). She still gets a chocolate bunny in her basket but I like coming up with other ideas for the eggs.
1. Tattoos/Stickers - These are one my of my daughter's favorite things! She gets excited seeing the different designs and types. If there is one thing she loves it's stickers and tattoos bonus they are inexpensive and usually have multiples per pack so you can fill more than one egg.
2. Party Favors -- If you hit your local party store there are TONS of options. Tiny yo-yos, mini nail polish, clappers, sticky hands, kaleidoscopes, bubbles, rings, bracelets, hair ties, popping frogs, etc...
3. Lip Gloss
4. Glow Sticks
5. Finger Puppets or small felt animals
6. Bouncy Balls
8. Erasers -- Can easily find loads of character ones that your child may like.
11. Finger Skateboards
12. Key chains
13. Army Men
14. Puzzle Pieces
15. Coupons -- My daughter loves when I make her coupon books. These coupons from Cute as You Please (found on Pinterest but links were all broken) are the perfect idea for egg filler.
Hope these ideas help you along!