After seeing a fingering poster online that another orchestra teacher had created, I knew I wanted to make a set for myself. I cut strips of black paper at various widths to show the strings from thickest to thinnest (1/4", 1/2", 3/4", 1"), laminated the poster, then used Velcro to mark where each note would go. Each letter name bubble was cut out, laminated, and Velcro-ed. I also taped a plastic baggie to the back of the poster to store the unused notes. At one school, I have a strip of cork board above the white board, so I use a push pin to display the poster. At the other school, I ran a couple strips of Velcro just above the white board, so I attach those posters with Velcro.
With beginners, I can have all the notes removed to just show the open strings, and then I can add the D string notes as we get there. With the second-year students, I can start with the D Major scale notes, or show those low 2 notes, or whatever it is we're focusing on.
This year I'm color-coding the tapes rather than just using black pin striping tape. For violins/violas, 1 = red, 3 = black, and 4 = blue (no tape for 2). For cellos, 2nd finger is red, and the rest are black (thumb goes behind red tape). On bass, first position 1 and 4 are red, and third position 1 and 4 are black. For the posters, I kept the red paper for the red tape notes and otherwise used blue paper. Maybe I should have added an extra column for the finger numbers, but for now it's working to stick the numbers on a string that we're not using at the moment.
Fingering chart note bubbles and instrument labels (Word doc)--should be enough for two sets; I printed the first page on red paper, the rest on blue--just double check it has all the notes you want
Fingering chart note bubbles and instrument labels (PDF)