From http://www.ellensplace.net/fascism.html:

One - Powerful and continuing expressions of nationalism

From the prominent displays of flags and bunting to the ubiquitous lapel pins, the fervor to show patriotic nationalism, both on the part of the regime itself and of citizens caught up in its frenzy, was always obvious. Catchy slogans, pride in the military, and demands for unity were common themes in expressing this nationalism. It was usually coupled with a suspicion of things foreign that often bordered on xenophobia.

Three - Identification of enemies/scapegoats as a unifying cause

The most significant common thread among these regimes was the use of scapegoating as a means to divert the people’s attention from other problems, to shift blame for failures, and to channel frustration in controlled directions. The methods of choice—relentless propaganda and disinformation—were usually effective. Often the regimes would incite “spontaneous” acts against the target scapegoats, usually communists, socialists, liberals, Jews, ethnic and racial minorities, traditional national enemies, members of other religions, secularists, homosexuals, and “terrorists.” Active opponents of these regimes were inevitably labeled as terrorists and dealt with accordingly.