We read How to Raise an Amazing Child and Montessori From the Start to get an idea of how to use Montessori principles with a baby. We are not following Montessori to the letter (the Montessori method would not include swaddling, for instance, because it restricts movement), but we are interested in creating a learning environment at home for Mavry's absorbent mind.
One of the things suggested from the beginning is to use different sorts of mobiles for the baby to look at. I found this post at How We Montessori and this post at Little Red Farm helpful in deciding which mobiles to make. There are some guidelines in hanging and using mobiles here.
In the beginning, we used just black and white ones. This one is from a mobile picture hanger I already had with some black and white sea creature art cards. It's hung above her floor bed where she usually takes naps.
Munari mobile. It took Colin (an engineer) to figure out how to balance it, so this was a team effort.
octahedron mobile is hung above her co-sleeper that is attached to our bed. She sleeps here at night, so she doesn't get as much awake time with this one, but she sometimes has alert time before or after sleeping when she watches these. If she's not swaddled, then she'll reach for them.
I hung the other mobiles from dowels or some bamboo sticks we had leftover from our wedding, but when I ran out of those, I hung this one from a wire hanger that I cut into three parts.
The Gobbi Mobile didn't look all that hard to do, but it turned out being the one I started first (well before she was born) and put off til last (just finished it a week or so ago). I switched it out with the whale/Munari mobile that we had rotated in the living room. (I think the principle is to rotate in a new mobile every few weeks, but we like having different ones in different places - after making them all, just two weeks of use seems too short!)
I made mine with styrofoam balls and embroidery floss. I started out by threading the floss through the center of each ball, but it took forever and got more difficult, so I ended up just glueing it on. It made for a less beautiful effect, but at least I finished it! Mavry reaches up for the balls now and enjoys watching them.
Another version of the Gobbi that looks prettier than mine and was likely faster/easier to make.