I normally ask for 50% on larger projects... but if I have a project that will only take a few hours I usually ask for at least 50% up front... but since it's so small and if they want go ahead and pay it all up front.... I'll give them a much better rate. Here's the one I started and finished this morning... he paid it all up front and gave me a great review after I was finished:
https://vborg.vbsupport.ru/showthread.php?t=132374