Waitt specialised in portraiture, but began his career as a decorative painter. His first recorded work is a coat of arms for the Earl of Hopetoun. He may have trained in the Edinburgh studio of the painter John Scougal and seems to have produced several different types of painting, notably still life. He married into a family with Jacobite sympathies and possibly left the country, temporarily, after the 1715 Jacobite Rising. He must have returned by 1722, however, when he resumed work for the Clan Grant based in Castle Grant, Strathspey. Waitt's series of portraits formed a unique clan gallery.