These have become a huge hit in our Montessori homeschool classroom.
In a more elementary Montessori style, I've set up materials shelves where the kids can pick and choose their own materials, rather than setting up a single tray with a set of materials and placing that on the shelf. (You can take a peek at these shelves, and an abridged list of what they contain, here in my classroom tour post.) I like that this set up enables them to be more independent about using the environment and more focused on cleaning up because they know where things live on our shelves. Also, this helps encourage team work when both older kids can work together, using their own set of materials and collaborating on the interpretation. (Usually it is just S telling T what to do, since she had already done all the activities.)
We have a beginning reader in our midst, and she is the one who loves science the most...so, I took many of the science activities in my NAMC manual and sketched out the steps with as few words as possible. I didn't worry about them being too neat, just accurate. And since they were handwritten, I used cursive. These sketches are in pencil on an unlined 3X5 index card. I laminated them all, then hole punched them, and then stuck a binder ring through the corner to hold them together. Then I made sure that we had all the needed materials on hand and let the kids have at it.
We usually review the new instructional sequences together, where they narrate to me the list of steps, and any necessary particulars. Then they set off to gather their materials list and I just do a quick visual double check before they get going (I usually don't say anything even if they missed something because it is very likely that they'll realize this all by themselves when it comes to that step in the process.) (Also, some materials I keep in my teacher-spot...like food color and iodine. And we don't use iodine or rubbing alcohol when D is around.) Every once in a while I'll check in with a "did you do, X,Y,Z?" Most of the time the answer is, "yes, that was step 3." I usually don't like to correct mistakes since most of these activities have a control of error anyway. Additionally, many of these activities are simple enough that I'll know what went wrong if they don't get a desired end result. And there are times after they have finished examining their result when I can explain briefly what actually took place, chemically, physically, or otherwise.
Below you can see the set of cards I did for Detecting Starch in Food.
So there you have it, a little part of our classroom and our typical day-to-day activity.
You can look back over the archives to see other science activities being carried out over the weeks...I think that there is at least one practically every week.