The easiest way is to use a soft towel. Think of it as a bath for your backside. When you step out of the tub, you reach for the towel, so there is no difference with a bidet.
The other option is to use toilet tissue, but that creates more mess, which needs to be disposed of down the toilet. The third option is to buy a bidet toilet seat with a dryer that shoots warm air to dry your nether regions.