Modeling wise, there is nothing different between 2D and 3D. I am not sure of which tutorial you are speaking of, but the traditional inkjet drop example (2D) is VERY good. 

Look at your results as the solution is progressing. Do the intermediate results make sense? Where are the problem areas in the domain? Are these accurately resolved?
Are you using the NITA (Non-iterative time advancement) approach? If you allow 30 iterations at the early timesteps, does it help it to converge better? 

Usually, it comes down to using a very small timestep and several iterations per timestep at the beginning. Later when we have a more established solution can we be more aggressive with the time step size and moving to NITA.

Good luck! These type of problems are never easy.