You've got a decent team. It wins you a few of your matches, so there isn't much to complain about. But, it isn't working quite like it should. Something is missing. I'm here to help you find out whatever that is. Making a team is hard, but sometimes revising a team is even harder. Here are three tips for improving on an already finished team. Buckle your idiomatic seat belts, folks.
Chapter 1: Tiny Changes, Or: They Prefer to be Called "Fun Sized" Changes
It's easy, when a team isn't reaching its potential, to simply decide that it isn't working and scratch an entire Pokémon, strategy, or, more drastically, the entire team. However, most of the time I find that a small change can make a huge difference. My Infernape wasn't working well at all. Then I gave him a Life Orb, and he became the star of my team. Just switch an item, or boot up a good TM and you may find that your small change has made a big difference.
Chapter 2: Back Up Pokémon, Or: "Yeah, I Play Football. I'm the 3rd String Bench-Riding Specialist."
Pokémon teams are made of six Pokémon. That doesn't mean that when you are making one you should constrict your self to only six monsters. Train a few extra so that, if you are dissatisfied with how your team is operating, you can just sub in a Pokémon from your box. I have a Serene Grace based Togekiss in my box. I trained it for my team, and was sure that it would be a great addition to my team. However, it just didn't gel with my team. I already had a ton of weaknesses to Electric, and adding the Togekiss just made that worse. Luckily I had already trained a Heracross (with Earthquake to stop those Electric types) that was just sitting in my box. I didn't have to go back and breed anything, because I already had done the work before, foreseeing that something could go wrong.
Chapter 3: Knowing When to Make Big Changes, Or: Letting Your Wailord Down Easy
Unfortunately, sometimes things just don't work out. That big strategy you concocted isn't as executable as you thought originally. But, then again, maybe you just need more practice to get it to work. How can you tell if your team isn't working because of it's design or because of human error in battles?
It's a tough question. Luckily, I have some tips that might get you closer to the answer. First, I'd recommend having a friend who is a bit better at competitive battling try your team from a spin. If they can make your team work, watch what they do different than you, and adjust accordingly. If they can't get your team at least a few wins, it might be time to scrap it.
Another tip, a less concrete one, is to just trust your intuition. Sometimes, you just know that your team isn't up to snuff, and won't ever be without some drastic changes. The tough part is that, if you want to improve, you have to actually make those changes, and that takes time. But, hey, we all enjoy playing Pokémon, and, for most of us, breeding and training is part of that, so it's not like starting a team over is exactly like pulling teeth.
I hope that helps! I'll catch you later, Pokéfolk.