I HATE surface prospecting. As a result, I have become rather good at it (cos I want to get it over quickly), so here are my tips.
Tip 1) Go to Deciat. There are around 12 landable high metal content bodies, and almost all requirements are covered, especially some of the more difficult grade 4s (tungsten, cadmium). Also, the system map already contains details of the content of all of these worlds without scanning them (may have to buy map and trade data, I can't remember). Although these aren't the highest content percentages that you will find on EDDB.io (they are still very good though), I have realised that some planets just spawn more nodes, so it's not the actual content that is the most important thing. The planets at Deciat spawn a LOT of nodes in my experience.
Tip 2) Where to land... In a giant crater, generally, the bigger the better. Either near to the inner edge of the crater, or near to its central mountain (the ones that have a central mountain). The reason for this is that it seems to be more unusual to find good nodes on flat land, particularly gold flavoured outcrops tend to favour an incline.
Tip 3) Always dismiss your ship, it creates a blockage on the scanner from GREAT range.
Tip 4) Choose a compass direction. Ideally as you are landing, you will have an idea either which way around the inner perimeter of the crater you will go, or perhaps steadily head towards a smaller crater within the big crater. Don't wander aimlessly, when you don't see a node on the scanner, return to your original direction and keep going til scanner pops. This forces the game to create new spawns for you and means they sometimes come in clusters (3 or 4 nodes all visible from one another, jackpot).
Tip 5) If you're looking for prospecting nodes, remember that ALL prospectable nodes show waves on the BOTTOM half of the scanner. Anything in the top half is man made.
Tip 6) The right nodes for the right materials. Bronzite Chondrite will give you mostly level 1 mats (iron, sulphur, whatever, based on the planet's content) and sometimes 1 or two of the rarer elements that are present. Mesosiderites are very good for rares (grade 4 mats and occasionally grade 5) but don't usually drop many fragments. Outcrops come in two flavours and in my experience are the most important ones, they come in a dirty brown flavour which usually drop a large amount of grade 1s (this is going to be your best source of iron), and gold flavour, which usually drop everything the planet has, skewing toward the higher value stuff. I always know I'm going to be happy when I see a gold outcrop. Lastly, and arguably best, but also rarest, metallic meteorites, usually have at least one G5 (technetium, ruthenium, etc).
Bonus Tip) Try to favour high G planets (0.6+) it makes it much faster to collect the materials and much easier to drive the SRV.
Bonus scanner wave descriptions) Bronzite Chondrite - a thin wave at the bottom of the scanner with two thin bands. Metallic Meteorite - a thick wave at bottom with single band. Outcrop - a thick wave at the bottom with 2 bands. Mesosiderite - a thin wave at the bottom with a single band. All metals make a clicky noise of varying tone.
I never have to farm more than an hour to get 25 of any metallic element I need and even more rarely have to look anywhere else except the first 4 landable bodies in Deciat.
Good luck.
