When drawing paths, I can easily constrain the next point to 45° increments by holding Shift. How do I hold these same angles when modifying existing paths? I want to ensure lines that appear level are actually level, and cannot think of a way to do it. Thanks.
Seems like a job for guides. Open View > Rulers and click the top or left ruler and drag a guide to the position you want other lines level with. You can also manually position guides by % or px, lock them with " Ctrl Alt + " to avoid repositioning and show / hide them with " Ctrl [ "
Also worth noting: If you set View > Snap to > Guides, anything you drag near the guide will adhere or "snap" to it instantly, making it more precise and easier to abide by.