If the XFL wants to really stand apart, do something like the NBA, allow 1 and done players. Use the old Cardale Jones line "We didn't go to college to play school" Get the freshman that have some name recognition to football fans after a solid year in college and then say they are draft eligible. Players like Jalen Hurts or Tau (however you spell his last name) from Bama would have a chance to go play professionally. Fromm from Georgia, JD Spielman as a RS FR. There are so many examples. Get the kids before the NFL can get them, lock them into a 3-4 year contract and boom you are getting the talent the NFL would have gotten, and you can build the viability of the your new league. Start in cities like SD, Portland, St Louis, Omaha, OKC, San Antonio. Have games in stadiums that hold 30-35K fans, this will generate a solid and rabid fan base in areas that either no longer have NFL or never have. There's plenty of players, you can build a 10 team league with an additional 55 players (active and practice squad) and have some highly competitive games that could rival the NFL. At this point it's getting the funding to make it work and a solid pay scale. Also, make it competitive with the NFL, salaries may be smaller, but make them guaranteed. Then the 50th through 53rd man on an NFL roster may look at going to the XFL to get all of his money. Players like Kenny Bell, who toil on practice squads can develop, and maybe make an impact in real game situations and get paid more. In the end, this could bode well for the athletes and open up more opportunities to pursue dreams.
Another big key, TV. NBC may have some interest, they don't have weekend games and could use some original broadcasting on NBCSports, Fox Sports may be interested on their cable channel. USA Network may also be an option since they have a good relationship with Vince and the WWE. It'll depend on if the XFL wants to go head to head with the NFL. Heck, even adding a $5/month increase to WWE network and stream games live via the network may be a solid option and allow the major highlight shows to show your highlights and you could potentially own your TV rights and not have to negotiate with a broadcast partner. This may also interest more viewers because of the lack of media timeouts and the added bonus of getting WWE PPV.
Lastly promote slight rule tweaks. Something like 'in the XFL, you'll know what a catch is'. Do some creative things like a FG from 50+ is worth 4 points. A way to increase scoring, make endzones 15 yards deep. Make more room and the field doesn't 'shorten' quite as much and the offense can get more points. Vince has never been shy of technology, put censors on the ball for TDs and first downs. Maybe test VR cameras on ref hats and player helmets, then fans can watch games after the fact with VR possibilities, imagine in 4 years being able to be 'on the field' when a major play happens, plus it'll open up so much more to the rabid football fan being able to be 'in the action' like that. And as much as we mock the 'hehateme' etc. Let the players have a bit more fun and freedom to celebrate and promote. There's a reason why Oregon gets so much love from teenagers, because of the freedom of their uniform. Let the teams and players have some similar type fun. I'm sure a major company like Adidas or Nike would love to be able to make new uniforms weekly for teams and have them for sale the next week in the home market.
There's a lot of potential if they don't go gimmicky with the scrum to see who gets the ball first. Everyone knows all eyes will be on the league when it starts, make it fresh, lock in some young talent and there is potential for this league to stick around. They may not last the long haul, but it may eventually force the NFL to adopt these new tweaks and not be so old.