tighten up

verb

To make sufficiently tight.
To fix something or make it correct.
“As noted in the last chapter, you should tighten up your argument and prose when you revise the first draft for substantive change.”
“He might do a third cut of silage, or he'd tighten up around the place in preparation for the winter, or he'd be still going off doing blocklaying jobs.”
To become tense and restrained.
“You must follow every change because every change affects your play. If another player loses a big pot, you must ask yourself how this will affect his play. Will he go on tilt? Will he tighten up?”
“He could feel himself tighten up as he prepared himself to ask her.”
To become, or make, more stringent and ungenerous.
“In May 1973 Honecker made another speech to the SED Central Committee, in which he appeared to want to tighten up the rules, as if his remarks in 1971 had been interpreted too liberally, but the VIIth Writers' Congress in November of the same year confirmed the relative freedom of the previous two years.”
“The church was tighening up on matters sexual. Until the middle of the tenth century it had been quite routine for priests to be married.”
To become focused and serious; to stop any vacillation or inconsistency.
“Plainly winter was at hand. "Just as well we started when we did," said Bill. "No tellin' when she'll tighten up." "May do it any time," Sam agreed.”
“You need to tighten up and stop being so fuckin' emotional for one in your life.”