I know that there is no set recipe for success, but I have had a couple of teams in a couple of worlds and I am getting really frustrated. I tend to lose at least one game a year where I am favored by 15 or more points, but have yet to win a game where I am the underdog. Is there some quick tips that I can use to at least be competitive year in and year out? It seems my teams plateau and then regress. All help is appreciated.

Ath/Def.  If you focus just on Ath/Def you will be succesfull, and probably make the tournament every season.  If you want to compete for titles you obviously need to do much more than that. The biggest mistake new coaches make is to focus on LP/Per, but if you ignore that and recruited Ath/Def without scoring you'd be more successful.   I looked quickly at your 2 active teams, at DIII your team ath needs to get closer to 50, and at DII 60, as a bare minimum.
I'd suggest getting a mentor, there are plenty of guys who will gladly help.
Good Luck.

I agree with Dan on DEF for sure, took a D2 team with an average of 35 DEF and pushed it over 55 and consistently made the tournament and started a season ranked. The key to consistency is being able to defend anyone really. If you can defend, the offense will come. It doesn't matter if you win by 1 point or 50 as long as you keep the opponent behind you in points you will win and Defense is typically easier than recruiting offense. Wierdly enough...

The defense advice is very sound.   Being good defensively is more than just a good DEF score.   It is a component of DEF, ATH, SPD and BLK.   Figuring out how the pieces work together is 1/2 the fun to me. 

Also, having a top notch scorer is pretty important.   In D3, there are lots of 80+ speed/per type guys.   These guys are pretty friggin hard to stop.  Having one of them makes your team a lot better.   Having one of them who is passable on defense is great. 

The recipe for winning is to recruit well. It really is. If you do that well, you will win. If you miss or take someone you shouldn't, you will suffer. Everytime I make a mistake on a recruit, I suffer for it and can easily trace back the mistake I made.

I also strongly suggest getting a mentor. It made a HUGE difference for me. Mentors don't solve everything but this is a complex game to understand. There are so many different ways to play and methods to recruit. How you schedule, who you schedule, how you structure your teams, what you emphasize, what you run. So much to learn. I've never ran a zone so I don't know much help I can be. I feel pretty good about the flex offense and the press. My teams usually are not that good but when they're bad, I at least can see why. That in of itself took a long time for me to learn. And still a lot left to learn.

Let me know if I can help in anyway. I've been there.

Your recruiting priority should be ATH, SPD, and DEF. Those are the most important ratings. IMO, every single player you recruit needs to be at least an average defender. I look at it like this - you can easily adjust your distro to not let a player shoot, but everyone on the court has to guard somebody. So you want to sign guys who are either great defenders, or decent defenders who do something else really well (score, rebound, or distribute).