Jamming is a whole field of study, and a great majority of military techniques don't apply to amateur ops. Methods vary with the type of jamming, and the operating requirement and limitations of the jammee.
-Ham jammers are either frustrated, angry or persons who get their jollies being social misfits.
-Don't encourage them by recognizing them, or commenting on their presence or effectiveness.
-Don't join in.
Approach 1: Move on. If no one is on the frequency, the jammers have no one to jam. Lack of an audience disappoints them, and shows their lack of 'power to influence others". Come back and work later.
Approach 2: Work through the jamming, Persistence.
-As pile up lessens you may get through.
-The jammer will get tired, and eventually quit.
-Perhaps the Dx team will get smart and shift freqs.
-Perhaps the Dx team will get smart and work varying split freqs
-Propagation may change favoring you
-Tighten fixed filters
-Adjust notch filters
-Adjust IF/passband/upper-lower filters
-Noise Blanker (NB) - OFF. Unless the jammer is using a pulsed noise with fixed repetition rate and 'hard' edges, this will either be ineffective or cause more noise artifacts in your receiver.
-Fiddle with DSP (I have severe doubts about using DSP in severe jamming situations and think you may do better with DSP-OFF.)
-Reduce RF Gain, to lower overall noise floor, but still hearing Dx.
-Adjust your operating freq just a few tens of Hertz up/down
-Use Compression (wisely)
-Increase Tx Power
-Use headphones vice speaker
-Change antennas; vertical, horizontal, fixed orientation.
-Rotate beam to place jammer in null. Don't worry about pointing at the Dx team.
Good luck, bill
p.s. Moving the 'net"/Dx frequency to a clear spot is always the best approach. Even if for a few minutes. Jammers must recognize the loss of target, search, and set up jamming again.
Short of changing freq's, calm persistence pays off. Eventually good operators will find windows of opportunity to pass traffic. Don't let the jammer get your goat. Accept the challenge of beating the jammer at his own game.
p.p.s. If you must stay on frequency, then sit back, enjoy the show and wait for opportunities. Rate the jammers' sense of humor. Identify the various techniques he uses. Can you find a pattern, or predict his next move?
The ultimate questions: Will he play "Stairway to Heaven"? and how often? (good for side bets).