Example : Resistance to the manager's plan built up quickly.
Pressure is building up at the Indian-Pakistani border.

Synonyms : build, build up, progress

Example : We worked up an as of an appetite.

Synonyms : get up

Example : We worked up courage.
Build up confidence.
Ramp up security in the airports.

Synonyms : build, build up, ramp up

Example : His colleagues worked out his interesting idea.
We worked up an ad for our client.

Synonyms : work out