All over the city, you will find advertisment for Massage Shops. A lot of them only offer legit massage (without any "hot experience"), but several shops will also offer at least a handjob happy ending.
In most of the more "naughty" places in Shanghai, happy ending massage is part the the service for around RMB 150,- to RMB 300,-. So means for that rate you will get a professional massage (most time oil massage) of around 60 to 90 minutes, finished with a handjob.
Most of the girls will also offer some more (for example touching, blow you or even full service), but this is up to you and the girl, nothing to do with the shop business.
In some shops you also can take out the girl to your hotel, if you will feel more safe there (for that they will charge around 50 RMB more for "outtake").
For a tip of around RMB 100,- to RMB 200,- you should get the girl naked including touch her, for around RMB 200,- to 400,- you should be able to get more service, but not so many girls will offer that.
If you have any experience with a shop that is not listed on our page, you also can leave a review here. Thanks for sharing your knowledge!