Correcting Oil Paintings

Scraping - correct as you work; don''''t try to cover up wet paint by painting over it, scrape that paint off the area with palette knife (wipe the blade on a rag ) will leave a ghost image which repainting will cover.
Wiping - dip a clean, lint-free paint rag in solvent and scrub away wet paint after scraping the excess with palette knife; this eliminates the ghost image.
Repainting - to repaint a dry canvas - gently sand area with steel wool or fine sand paper (takes off some paint & roughens surface a little); moisten surface to be repainted with some medium on a clean, lint-free paint rag; then paint over; ** don''''t be too careful when repainting, be spontaneous, don''''t leave sharp edges