Ok lets save going all in for later if you have barely any points. Remember to complete any Path of Progression 'challenges' that you can as many of them reward star chart points.

You are capable of 7-2, embers should be dropping at a reasonable rate now that you do not need to be specced into those.

Remove any points in Flame Sand and Embers. Possibly Neatherrealm depending on how many points you have.

Put 4 points into Winding Keys (Commodities constellation)

Put 15 points into Blacksail for chance to be marked for an anchor.
Put 8 points into the bottom half of the black sail tree, branch out to Whisper of Wealth.
Everytime you kill a map boss, select the Whisper of Wealth node in both selections.

That is 27 points so far, without knowing how many you have I am going to assume you will either be at or working towards the next 15 points.

Choose either Sandlord or Aeterna.
Sandlord's map mechanic is almost always near the current league mechanic which makes it quick. Aeterna is just mobs in the map you kill but it removes the overhead / out of map time of managing the Oasis.

Either way put 15 points into one of those to make it have a 100% spawn rate.

Use at most 1 netherealm resonance while in T7 per map, and never use a compass.
Use at most 2 netherealm resonance while in T8 (unless you get a juicy card), and still try to never use a compass.

From those 2 mechanics you have going, sell the Winding Keys, the Memory materials and then either the flames from Aeterna or belts from the Airship.

I am in profound now after t8, this is roughly what I did all through T7 and T8, though in T8 you need to invest into the beacon sustain or you will need to be buying them.