I would say there is 3 ways to improve the quality and excitement of the premier league or english football without too much tinkering with the structure.

1. Winners of the FA Cup = Automatic Champions League Qualification (Runners-up would get it if the FA Cup winners are in the premier league top 3), would love to see all these clubs field strongest XI instead of messing around and putting fringe players in for important squad players which can hinder any cup progression and it would certainly make the FA Cup much more exciting and a big prize at stake

2. If not having the winners of the FA Cup getting Champions League, Then its the playoffs, 7th vs 4th, 6th vs 5th, 2 legs, final at wembley, I don't care the top managers/chairman don't like it when they voted on this a while ago, I would of put it in place whether they liked it or not, it opens up things again, Everton, Tottenham, Liverpool and Newcastle and possibly a few others could have a great season and not get a true reward because Arsenal, Chelsea, Man City and Man Utd have the current stronghold on our top 4 places. Would give us all a very entertaining end to the football season every year without knowing who is going to be in the champions league and having it all to play for, the 3 losing clubs would benefit from an extra full round of gate recepts + tv money which would keep them in check with the other clubs qualifying for champions league.

3. and most importantly for the good of english football and our national team development and fixture congestion that managers always talk about... Get rid of the league cup, Sorry Bradford City and Swansea fans but its true, the competition dubbed the 'mickey mouse cup' really has to go, plenty of understrength sides in a competition that a lot of teams don't really care? Yes its great if you make the final and you have a chance of winning a trophy but what does it really mean? nothing. The league cup was brought in for extra revenue years ago, but with big TV deals going around the competition isnt really neeeded, premier league play 38 games a season and the football league play 46 games a season, If Championship clubs complain about lack of league cup, chuck them in the Football League Trophy. The football league would benefit for having 6 extra slots a season for postponed games or as above to accommodate those Premier League Champions League Playoffs.

I'm an Arsenal fan and I would love to see those playoffs just because it brings excitement between 4 big clubs to fight for that champions league place, even if Arsenal finished 4th, I wouldn't feel that we should have the right because we were 4th, I'd like to see that end of season special event, but they shelved them a couple of years back due to the lack of votes, even though they actually voted 11-9 in favour, they needed 14-6 to pass it on.