All shortcuts offer the choice between creating a new draft or appending to the last modified draft. The latter is most useful for the shortcut that quotes from a PDF, which I mostly use for creating excerpts I read on my iPad.
Any ideas for improvement are welcome! (split into two posts, as I cannot post more than two links per post as new user, sorry)
for Images: Image as Inline Markdown URL (uploaded via imgur)
for reading & excerpting PDFs: Quote from PDF with page no. reference