Microsoft Powerpoint is quite a powerful tool for mocking, if you know what you are doing.
If you copy an SVG file into PowerPoint and double click on it you can convert it into a shape, in which you can completely pull apart and edit individual elements. Logopedia is a great source for SVG logos.
this is how i created my NBC Sky News Mock
I’m not usually a fan of gradients, but I have recently figured out nice gradient making, using layered elements and transparency.
You don’t need flashy software for mocking. I hope this helps any aspiring mock artists out there.