Patrick Straub
Webentwicklung & Suchmaschinenoptimierung
wizible.de
kontakt@wizible.de
+49 17685918220
maybe a QR code (am unsure because I don't know how it looks visually and if it is modern)
What to avoid
Nothing colorful, childish.
References
Stock images
Client requested you avoid using stock for this contest.
Stock images are licensed photos and vector files. Please tell the client before you submit designs using stock images
If you use fonts that require a license, confirm with the client they're ok with it. For licensing reasons, it is better to provide your client with information on how to acquire the font rather than providing the actual files.