Cleaning up is hard to do for little people. Sometimes, a big contributing factor to the whining and crying is that the children aren't ready to transition out of the activity. At other times, their idea of cleaning up and ours are very different. Whatever the case, your daughters have started a pattern of getting upset when it's time for a little order. That's not your fault, and it's not their's, it's just the way things are.
If it were me, I would relax on the cleaning up for a week or so, then try a new approach. Here are some ideas:
LABELING and BASKETS: Kids often like to sort items into categories. Take advantage of this tendency by buying baskets (They don't have to be expensive--they sell them at the dollar store) and making easy-to-understand picture labels to put on each basket. Doll clothes can go in one basket; play food in another, etc. Labelling helps children find things and put them away more easily than being told "No, that doesn't go there." It gives order to a room. That's why so many preschool classes have labelled bins.
MAKE IT A GAME: No one likes to do something that's presented as a 'have to' and a chore. I like to be less about the cleaning up and more about the activity. "Can you find all the things that go in this basket? We are looking for all the cars. Where are they hiding?" Put your effort into the fun game you are inviting them to play. Some of this may require a little bit of imagination and enthusiasm you wouldn't normally equate with picking up ("Ooo! I found this red car hiding under the doll bed. Found you, car!"), but our attitudes go a long way in determining how our children will feel about any given task.
WALK THEM THROUGH IT:Most preschool teachers (except the ones who aren't quite truthful) will tell you that most children need adult guidance to get things put away. Even much older kids would rather not put things away. So, if you tell children to "Clean up" and then walk away or just sit there and expect them to hop to, you're asking to be disappointed. Kids look at a mess and often have no idea where to start. Kids need some cues in that regard:"Let's see. The dolls are all out of their bed. Let's help them come to bed now." Or ask your girls what they would like to pick up first, the blocks or the animals? (Note: competitive children may work better at picking up separate types of items, so they are not fighting over toys during the process.)
KEEP TOYS TO A REASONABLE AMOUNT: If you have ever walked into a preschool, you will see a few baskets of toys out and the rest of them stacked up on shelves or in a closet. At home, we rotate toys, putting away the baskets of toys that are only emptied out but not really played with and keeping available those toys that are used most often. I rotate my toys every week/two weeks or so by replacing the toys children have lost interest in with a "fresh" basket or two. IF the kids ask for some toys that have rotated out, it's fair to ask what it is they are ready to put away for a little while, and fulfill their request.
POINT OUT THE ADVANTAGES OF CLEANING UP AND MAKE IT ROUTINE WHEN POSSIBLE: Taking a moment to comment on how "we have so much more room to play now" is a positive message in learning why it is that cleaning up is important. Grab those opportunities as the kids go from one activity to another, and mention to them that they'll need room to play with larger scale items, like blocks and the like. "How can we make room so we can play with this?" But only ask them to clean something up when you can see that they are done playing with those toys and have moved on. Imaginative/dramatic play may require dolls, a play kitchen and a shopping cart, so be understanding. Clean up two times earlier in the day, so it's not one big mess when they are tired at the end of the day. In fact, if you can do a cleanup
after a afternoon snack, before dinnertime, you have helpers who aren't tired and much smaller cleanups to take care of.
USE A TIMER:Sometimes the mess is really, really big. Have the kids set a timer for five minutes to work, then to take a break with a book or something else pleasurable. Work with them, and when the timer goes "ding", take a break.
Last of all:
AVOID USING PUNISHMENTS AND REWARDS TO GET CHILDREN TO CLEAN UP: A lot of kids are really fine with having all of their toys out, so penalizing or bribing is really not a great way to end the tears. You can give some guidelines as to your own comfort --"I'll be happy to bring out the legos when I see the animals and cars picked up. It's hard to pick up all the legos when we have all these toys out, and I don't like stepping on them." or "You'd like me to get out the marble run. I'm happy to do that after we decide what we are going to put away first." Then, when they decide, offer to help. Otherwise, if they don't want to put their toys away, I like to give them a little breathing room. "Let me know when you want a little help putting those toys away, then I'll be happy to get out the marble run."
I've used a lot of examples of what one might say, because, as I've said before, attitude makes all the difference. Once the kids aren't busy fighting you, they can make up their own minds about their priorities. It's never perfect, and kids will whine about it even as they do it, but let them whine. They are just venting. And don't allow the blame game to start: everyone helps, no matter who got it out. (Unless, of course, it's cut and dry that only one child used the toy, in which case, that's fine. But only if you've witnessed it with your own eyes!)
Sorry this is so long, but I hope it helps! It certainly did with my toddler groups.:)