Quoted from atg1469:This is one aspect of the game I'm still struggling to grasp, mind sharing your typical strategies for gem placements and why?! I'm a relatively new owner and digging the game, but I'm basically throwing gems all over the place and hoping for the best!
If you're just trying to reach Thanos, do this:
Mind Gem first, put it on Black Widow, she's the easiest to bring to level 1 and 2 frequently for the better uses of the gem. Make sure you read the rules and actually fully understand how this gem power works.
Power Gem on Black Panther, he's the hardest to level and also has the most important level-1 power to keep active (longer combo timers.)
Soul Gem anywhere (easiest is the drops) - but then when Thanos Attacks happens, hit the Soul Gem and trap up and then intentionally time out the mode to let him have it. This is better than risking losing a ball trying to complete Thanos Attacks, since you can win the Soul Gem back in other ways (score a super in Black Order MB or win Battle Royale, or actually you don't need it at all to reach Thanos.)
Next quest depends on the state of the Mind Gem at that moment. If it's low or level-2, do Reality Gem next (if it's level-2, complete Reality in one hit of the mind gem.) Reality can go anywhere, the Captain Marvel ramp is fine.
When Mind Gem is at level 1, do the Time Gem quest, and use the three Mind Gem booms for all three drop target hits. Time can go anywhere, either drops or Captain America is fine.
Space Gem last and goes wherever is left. (Do not chase the Space Gem's power, it never works out, any complicated thing you're trying to do by moving the gems around is easier to just directly shoot whatever you're trying to do instead.)