The best: perhaps from fruit, that growing at the top of the tree being generally the best, as partaking most of the sun. A tip-top workman; the best, or most excellent Workman.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
To Tip * Tipperary FortuneNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes