The answer: enter the medina at the right gate, then follow one continuous named route and never improvise. Fes el-Bali has multiple gates (Bab Boujloud, Bab Rcif, Bab Guissa) and a riad may be far closer to one than the others, so choose the gate based on your riad's quarter first. Once inside, treat every turn as expensive - a wrong turn costs ten minutes - and use a photo route from the gate to the door, since GPS cannot see through the walls of the medina.
Fes el-Bali is the biggest car-free urban area on earth: thousands of lanes, no vehicle access, and doors that look the same for hundreds of metres in every direction. Even locals from other parts of Fez can get turned around in it. Finding a riad here is a navigational project, not a walk.
The medina has several entrances and they are not interchangeable. Bab Boujloud (the blue gate) is the most famous and the usual tourist entry. Bab Rcif serves the southern and eastern quarters and is often much closer to riads in Rcif, Andalous or the Talaa Kebira side. Bab Guissa is on the north side. Ask your riad which gate they recommend and, more importantly, which gate their porter would use - most riads offer to meet guests at a gate for good reason.
Within the medina, two long routes do most of the work: Talaa Kebira (the big hill) and Talaa Seghira (the small hill), running between Bab Boujloud and the Qarawiyyin area. Many riads advertise their position relative to one of these. If you can walk a main route and then make one deliberate turn, you are fine. The danger is the shortcut: a lane that looks like it connects two main routes often dead-ends at a locked door or turns into someone's courtyard.
It is common for someone to appear and offer to guide you for a fee, and equally common for a helpful-looking person to claim your lane is closed ('fermée') and lead you a longer way. Practical rule: agree on the destination and the price before following anyone, or better, arrive with the route already saved. If you must ask, ask a shopkeeper inside a fixed premises rather than someone who starts walking with you.
Medina doors are heavy wood, often studded, with brass knockers, and the riad name may be a small plate at eye level or only visible once the door opens. Behind the door there is usually a bend (an intentional privacy break) before the courtyard, so you cannot identify a riad from the street by looking in. Save a photo of the door itself in your route - it is the only reliable identifier on the lane.
Cars stop at the medina edge - expect 5-15 minutes of walking with your bags, sometimes with steps. Arrange a porter or ask the riad to meet you at the gate if you arrive at night. Then follow a saved Fez photo route from that gate, one photo per turn, offline. For context on what accommodation costs elsewhere in the country, our Morocco hotel price comparison is a quick read.