In blackjack, the house edge over an inexperienced players is around 2% [source]. Thus any small rule-adjustment will do the work.
My suggestion is not to change the rules but to simply remove half of the 2-6 from the deck. Card-counting players are waiting for exactly this situations, known as hot-deck, then they know that they have the edge over the house thus they shift from 1$ bets into 10K$ bets.
To put it simply, if cards of smaller ranks (2, 3, 4, 5 and 6) are
dealt and removed from the deck, their removal will have a positive
effect on your expectations. In other words, their removal increases
your advantage. As for the cards of higher ranks (10, J, Q, K and A),
their removal has a negative effect on your expectations. It simply
means that odds of creating a blackjack hand when these cards are
removed from the deck for the player are lower. Finally, the removal
of 7, 8 and 9 has almost no effect on your expectations.
EDIT: removing all of the 2-6 is too big of an advantage, I think it is better to remove just half of the 2-6. This is because removing all of the 2-6 will create wired situations where players almost know that the dealer will go bust.
Other rules-adjustments that can move the edge to the players:
- Players win ties.
- Dealer stand on 18 instead of 17
Suggestions from a variant called Player's Edge 21:
- blackjack payouts to 2:1
- Two suited and ranked player face cards are an automatic winner. This includes beating a dealer blackjack.
- Late surrender is allowed.
- The player may double at any time. This includes on any number of cards, after splitting, and after doubling. The maximum number of double per hand is three.
- Re-splitting aces allowed.
- A player 21 always wins.
- Player blackjack beats dealer blackjack.
- Player may hit and double down after splitting aces.
- Player may surrender after doubling, known as "double down rescue." The player forfeits an amount equal to his original bet.
- A five-card 21 pays 3 to 2, a six-card 21 pays 2 to 1, and a seven or more card 21 pays 3 to 1.
- A 6-7-8 or 7-7-7 of mixed suits pays 3 to 2, of the same suit pays 2 to 1, and of spades pays 3 to 1. These bonuses pay after splitting but not after doubling.
Suited 7-7-7 when the dealer has a seven face up pays $1000 for bets of $5-$24 and $5000 for bets of $25 or over.