Easy Money And Items
Go to Beta Centauri and mine all the moons. All of the moons here have 48 of all three items and the respawn rate is very high. You can easily fill your cargo holds relatively quickly. Then, go somewhere that will buy your cargo and sell it all. It helps if you have all of your Psi so the patrols do not nail you for having Contraband. If you successfully fulfill all three counts, you will get 192 of each item. If you are looking for specific items that you need for crafting, the ones available here are as follows: Food, Polymers, Minerals, Alloys, Technology, Isotopes, Crystals, Gold, and Contraband (everything except Medicine).
Always work from the outside to the inside on the perimeter to avoid large shifting of gems. This will prevent cascades, which will cost time to recover from. Do not go out of your way for clock matches. Try to incorporate them into shifts that you have to do anyway to get the target pieces you need in place. Start grouping clocks in the same general area and they will match on their own without you taking extra time to align them. Always look at the next color gem so you do not have to waste time scanning for its location.