It depends on how many risks you're willing to take for graze-- SA scoring is more about adding one technique at a time, rather than following a route, though there still is power management to consider.
I'd recommend finding a replay or two to learn from-- the world record can be helpful to see the variety of techniques, while replays that are slightly above your current skill level can help gauge which techniques would be easier for you to learn.
For my 866m score I developed a route using the relatively safer techniques I'd seen (mainly based on Seppo's and Heartbeam's replays, which were 1st and 2nd on MotK at the time). I think Sakurei copied the WR route.
Note that the left side of the PIV multiplier (yes, the part that resets if you die) matters much more than the graze multiplier on lower difficulties. It starts at 50,000 on Normal, and the stage 1/2 star items add about 19,000, basically an additional 1.4x multiplier on top of the graze multiplier.
So the general SA Easy/Normal route involves a suicide at the start for power, speedkilling Kisume and midboss Parsee to gain as many star items as possible, and not dying for the rest of the game while collecting as many point items as possible. Then bombs are used wherever they'd be worth the most graze, or occasionally for point item collection like against stage 4 Orin 2.