Collocations for optimistic - adj.

appear, be, feel, look, seem, sound
become
remain, stay

extremely, fairly, very, etc.
highly
He remained highly optimistic that an agreement could be reached.

excessively, hopelessly, incredibly, overly, unduly, wildly
These estimates were wildly optimistic.

a little, slightly, etc.
reasonably
generally
a generally optimistic view of the future

cautiously, guardedly, quietly (esp. AmE)
I don't want to exaggerate our chances, but I'm cautiously optimistic.

about
He's very optimistic about his chances.

Optimistic is used with these nouns:
assessment, estimate, expectation, forecast, mood, note, outlook, picture, prediction, projection, scenario, view