Nobody is born perfect.
I've had a hand in running competitive club practices for two seasons now and I can say with certainty that how you practice is how you will play come game-time. Now, you can certainly play worse than how you practice, but you likely won't play better (at least not for a sustained period of time, e.g. multiple tournaments).
Players who think that practice is the only time to work on their game are just plain wrong. Most of the hard work and grit must be done on your own time. And that is precisely why so many players don't do it. No one is there to watch you and encourage you when you're hitting the gym, turning down fried foods, or going to bed early in order to get the rest that so many people overlook. You can add to your fitness at practice, you can add to your throws too, but the real grunt work is for your own time. Never forget that.
Practice time is precious. It's a short period - just a couple hours - when you get to be with your whole team. If you waste that time, you do so at the expense of your individual development and the future success of the team. It's fine to joke around and shoot the shit while you lace up. But once warm-up starts, you need to be dialed in. How you warm up in practice is how you will warm up before the finals of a tournament later in the summer. Mental preparation is a common asset amongst all successful clubs. From the moment you start to warm up you need to be visualizing how you are going to do what you need to do to help your team win.
Being lazy in practice is inexcusable. Failing to step out when throwing, or using 'league' throws are examples of this. It is better to go all out for 70% of practice, exhaust yourself and de-cleat, then it is to go half-assed for 100% of practice. Practice isn't easy. Frankly if you go because you like to scrimmage and want to see your friends, then you probably aren't cut out for what it takes to succeed at the touring level. No amount of natural talent can exempt you from the hard work and dedication you need to put in at practice to succeed. Think of A.I. bitching about, "Practice? We talking' bout practice?" Then count how many rings he has. None. It's guys like Kobe and Jordan - guys who have the talent, but still put in more work than anyone else - those are the guys who rack up rings.
You do want to take advantage of the opportunity to expand your play and gel with teammates at practice. But there should be a sustained period - from the time you start warm-up till the end of the last drill - when you are doing everything within your mental and physical control to make yourself and your teammates better.
Practice shouldn't always be fun. The product of hard practice is what's fun: glory.
those are some of my thoughts.