Guides are very helpful, and I use them all the time. But, when you need to create them, that can be really time-consuming.
Fortunately, there is little helpful feature that will save you some time and energy while creating guides! InDesign allows you to draw both horizontal and vertical guides simultaneously!
As you can see from screenshot, it’s pretty easy to do it. All you have to do is to simply hold Ctrl (PC) / Command (Mac) and click-drag from square where the two rulers meet to desired place.
That’s all! Easy and effective!