The initial question was how do you do it? The answer is simple: Catch moves with enough size. Either medium size and large moves, or bigger size and smaller moves Now, obviously not every day is a winner - that's completely unrealistic.
I assume you are referring to position trading...as in scalping, there's definitely a limit to the amount of size you can use.
well ... you need to have an edge ... and your account even if retail ... needs to be large enough not to force you into going "all in" just to make this arbitrary number also you cannot go into the next week saying ... "well I made 5K last week so this week 1k a day is a done deal "
The guys I know who average $5K/day don't actually make $5k each day. They make $30k one day, then 5K the next, and then they lost $7K. At the end of the year, they average $5K, but in reality some aspect of the 80/20 rule applies. Most of their profits come from a small percentage of their trades.