Pause and unpause on specific frames to get the same run every time. For this, it will help if you install Sharpkeys from https://github.com/randyrants/sharpkeys and remap right control (or another if it's better for you) to either tab or escape, depending on what version you're playing. Now you can press pause on one key and then the other almost immediately afterwards to have a manual frame advance. For the known list of pause buffers, see the #buffers channel in the Discord server. This is obviously a rough guide. If you need any more advice, you can ask in the HWSR Discord server, but it's mostly a matter of getting the timing down with practice.