Bounty for heavily nexted bases
Add a gold/elixir/trophy multiplier bonus for bases determined by the amount of times they get nexted over. The assumption is that bases that get nexted over repeatedly have strong defenses or purposely carry very little elixir/gold. It would make all bases vulnerable to attack and make shield-riders who leave their TH outside less valuable for attacking. It would also encourage players to attack stronger bases instead of beating up on weaker ones where 3 stars is guaranteed.
I'm in Masters 2 and I see tons of bases with lvl 3 inferno towers and lvl 4 x-bows that I bet never get attacked, because there's no incentive attacking a base like that where you'll spend 500k elxir to get 1 star and 5 trophies. If there were a million elixir bonus because the base has been nexted 50 times or a 5x trophy multiplier, then it would be more appetizing to attack.