The standard knee-jerk reaction is to cut back on marketing, sales and planning. Some cuts might be necessary, but to succeed you need to be make surgical cuts, across the board cuts. For example, look at your marketing spending and see what is working well and what isn't. Cut back on everything that isn't delivering results.
If you have any deadwood in your sales staff, of course you should let them go.
But if others are good but just in a slump, try to negotiate a lower base in the short term. Most people would rather 80% than nothing.
Slow times are the best times to re-evaluate strategy and rethink your business from top to bottom. Have markets shifted? Have new competitors joined the fray? Have you fallen behind on technology? Don't just throw stuff at the wall and hope it sticks. Do some market research, talk to your customers, analyze your competition. Then make wise decisions.
Fast growth is what everybody seems to want. But slow and steady usually wins the race.