How about: contracts can only be guaranteed for a maximum of three years. Contracts can be longer, but there must be a team option every year thereafter. (Or: a twofold system: there's a player option for a smaller contract and a team option for a larger contract. So if the team wants to keep the player, they have to pay him more. Conversely, if you're a crappy player who lucked into a long (ish) contract, you get the option, but the team doesn't have to pay you as much as if they wanted you.)
1) I love this, three year max totally guaranteed contracts, with options after that. (only applying to bird rights or teams under the cap), so you can do a 4, 5, or 6 year contract but basically there's a floor and a ceiling. The team has an option at 1.5X the deal amount that they have two weeks in the offseason to decide to use or not (directly before free agency). The players have one month to decide whether to exercise their option (@ 2/3 of the prior salary), during this time they can negotiate and field offers from other teams and still have a fall-back, teams can also negotiate with other players at the same position, true market valuation at the present time. And I wouldn't feel bad for teams who made shitty deals for players paying 2/3. Perhaps the team could amnesty the player if they opted in and the salary wouldn't count against the cap but the team would have to pay the player.
2) Break the MLE in half. Two 3 year, 3 million dollar MLE's available. No five year deals w/12.5% raises each year to journeymen. This will encourage players to stick with the team that drafted them, or that team getting compensation back.
3) Franchise player tag, just means you're allowed to sign the player for a larger signing bonus%, and other teams have to give up a 1st round pick w/in three years (of their choosing) to sign the player in free agency. You can only designate one player at a time, can only be used once every three years.
4) Bigger signing bonuses available, maybe 15% of a deal (which don't count against the cap), and only 5% raises each year of a contract. This allows players to get paid for potential now, instead of later when they don't pan out or get injured.
5) Reduction in games for the season to 70, four pre-season games (two overseas) per team. Eliminate back to backs, get the same number of games on TV (where a lot of the revenue is). Let's face it, the season is too long, losses mean two little, and at the end lots of teams are resting players, not good for the league. I would suggest along with this eliminate four teams from the playoffs.
So the season would be approximately 70 games, four divisions instead of six (I'd suggest west coast, central, NE, SE), play teams in your division 4X, everyone else twice. The division winners get a bye in the first round, then the top 4 at large from each conference.
/\ both of these moves would add much significance to each regular season game w/o really decreasing the revenues IMO. You'd still have all the key matchups televised, and the smaller markets would likely get more exposure.
Also players might be willing to drop 15% in their current contracts if they didn't have to play back to backs and cut out 12 games a season (along with four teams from the playoffs with no chance at winning). The level of competition would increase dramatically, don't you always think I wish the regular season games were like playoff intensity, this would change things a lot.
I feel like these suggestions would increase competition and fan interest, help out small market owners, and the players would possibly make more in the long run too.