Write down your bike identification numbers - vehicle ident number, EIN, or something like this - that are etched into the bicycle frame. This helps you identify a bike, even if all branding customizations are gone - or if someone stole a bike. Cykel provides you a field for this.
Try to make sure that people recognize the bikes as sharing bike right away. Your bike can be labelled with signs or stickers, to make it more visible. Note that the stickers should be outdoor compatible - labels from a cheap thermal printer only work for a few days and are then destroyed by sun and rain.
In our deployment in Ulm, we’ve begun with simple labels - and learned that thermal labels are not very convenient the hard way. After that, we experimented with cardboard and laminated paper on the sides of the rear wheel. This worked nice, so we upgraded to lasercut pvc sheets and placed individualized stickers with the bike number and qr code on it.