West towards Dijon, East towards Germany , or South towards Bourg-en-Bresse, Lyon
You have to go to the péage of motorway A36. Take bus 8 in direction of Valentin from the bus stop Battantin the centre of Besançon until the stop Echangeur Valentin (it's almost the end of the bus route). Then walk in the direction of McD and you will see the péage. You should use a sign or ask people because cars are going both south/west and east from here. There's a gendarmerie here, but policemen don't seem to care about hitchhikers. Note that there are no buses on Sundays so you should walk there, it's about 6 km.
From the center, you can walk to "rue de Vesoul", and there is a bus spot a little bit more after the station AVIA, next to a school. Using a sign with Valentin should be easy. It takes about 30 minutes walking from pont battant in the center.
Southeast toward Pontarlier, Lausanne
The spot is at the petrol station, and never takes more than 30 min (can be 4...). For this you have to walk out of the centre to the crossing called Rivotte (near the tunnel under the citadel), then follow the road in direction of Pontarlier. Next good point is the round-about close to Valdahon, don't take a ride which goes closer than this point.
Same spot to get to Valentin from the center as described above. Wait for a long ride, or ask if people can stop you in "Cayenne", or next to Quenoche where cars have to slow down. Don't go to Rioz.
North towards Gray
Take tramway 2 or 1 until the end, direction haut de chazal. Walk 20 minutes to Franois, until the second roundabout. Take the D75 direction, and stop at the next roundabout, then it's easy to get a ride towards Marnay and Gray.
You can also go to the motorway A36 entrance from this spot.
A local bus ticket costs EUR 1.40 and is valid for one hour on any buses or/and tramway. Be careful on Sundays there is no bus to go the péage! But you can hitch to an other péage from the end of the tramway line haut de chazal. Look for information towards Gray.
You want to know where to camp? Where are the markets, have nice drinks or buy clothes in secondhand shops, go here, and share with us if you know more useful informations : MAP
For example, there is a place where locals are making free vegetarian meals for everyone each last sunday of the month. Check it out!