For example in Illustrator I will have a giant artboard with 20+ different screens with arrows connecting them and notes spread all over the place. This is how I wireframe/design. Here is purposefully vague zoomed out version so you have an idea:

http://f.cl.ly/items/230E3Z3U2u1A1N2i1Y0N/Screen%20Shot%202014-06-24%20at%2020.10.48.png

I can do the same in Sketch but performance starts to suffer a bit after only a few screens. I wish Sketch was better in that aspect since it really is much better in all kinds of aspects related to UI design such as managing layer styles, actually rendering pretty text, dealing with effects (shadows, blurs), border radii and not frustrating me with too much pixel rounding issues.