The double exposure opportunity you can even experiment with motifs, are well in the double Photos dark backgrounds.
The strength of some small aspect ratio with the humble so that relatively large depth of field is also at the same time a disadvantage: The photos are quite small. Although the camera has an infinity position of the lens, I advise of landscapes.
The best photos are where the main subject as large as possible fills the small format. Portraits, 2-3 people in 2 meters, this is quite good.
The macro function (theoretically from 30 cm) is best done so by 50 cm, but do not expect any miracle sharpness.
Even at night shots you can dare the long exposure (on tripod).
Average images need at room temperature for about 3 minutes until they are developed by. Tests have shown that the development times with film temperatures around 2-4 degrees can certainly extend to four minutes.
In particular for landscape photos, make sure that the emerging picture does not "stick" to the left hand remains.
While you can increase or decrease the exposure, but through trial and error "may cost the photos ...
The viewfinder even has a parallax. Schön would be a tripod mount for landscape mode.
Witzig is the self-timer, which even allows two shots. The flash is sufficient for recordings by two meters.
The film cartridge can be well used as a storage box for photos after being removed from the camera if it has been recognized the trick with the small sides film.
The Instax 90 Neoclassic is taken seriously by the people and is immediately after the first instant the heart of any society, but: Everyone wants to have an instant picture immediately. So when used at a party should always be there two double packs !!!
Summary: If one recognizes the limits (of the format and the two-lens objective) that Neoclassic makes even fun. What more do you want?