If you're a verified service provider, you won't have to do anything extra – clients can already book your services. You'll be able to view every task request separately, and choose whether to accept or decline it.
You'll also have the freedom to select the working hours that suit you best as you'll be able to modify your profile's visibility to clients at any time.
What if you're on vacation or simply too busy? You can turn the orders off completely. This can be done by going to your Account and clicking on the option Temporarily pause orders.
Once you do that, you'll immediately see a notice informing you that orders are paused. You'll be able to turn them back on and start receiving client orders again at any time.