Tips on how to better role-play your character can be found here. If you have your own suggestion/tip, Contact Me and I'll post it up.
When sending in your email update to your ref, use good grammar. There is nothing more annoying than when a ref opens an email from one of his players and has to re-read it to understand what the player is trying to say. Not only is it easier to read, but it also makes your ref take you more seriously. It will also make the experience more enjoyable for you, as the player. If your ref sees that you're not putting any time into your updates, then he is not going to feel like putting much into yours.
Get into your character. The more descriptive you are with your updates, the more descriptive your ref will want to be for you. Be creative - let your creative juices flow. There's nothing worse for a ref than to open your email to see something so cut and dry that it makes them hate being a ref. Don't be afriad to try something because it isn't in the rules, if you try it and it doesn't work, you're not really much worse off than you were before you tried. If it does work, then hey you just did something that others might not have even thought about.
Remember, Planet Mado is a completely open rpg. You can almost always try something that isn't specified in the rules. That doesn't mean it is guaranteed to work, but if you role-play it well enough, your ref will probably at least give it a chance. Think outside the box. The rules and the normal way of doing things are the box, think of ways you can do things differently. Some might work and some might not. It keeps things more interesting and fun for all parties involved then if you only do what 90 other people think of as well
Have a goal in mind. Not to say you need to know everything you want to do right away, but it keeps the game more interesting than if you just train and spar all day and do nothing with your character.
Some awesome tips from Epyon:
Think about a history for your character and use it to tell stories and interact with NPCs and other players. It helps deepen the game and give your ref ideas and personalized quests for your character. Develop a personality for your character and decide what things make the react strongly and in what way? For those who don't have an appearance already written out for you character, do so. Make it detailed, from clothes to scars to any other interesting features. When moving about town, if for any reason your character is looking disgruntled, excited, wide-eyed, etc., say so. Let the ref know so he can let other players know it too. It's important to know.
Know that your character is not perfect. Think about some flaws for your character. Not everyone deals with everything perfectly and your character should reflect that. You can't expect to have a certain relationship with other characters or NPCs or masters, especially if you haven't even met them yet. Don't assume that a master wants to train you or your friends or act like these people owe you something.
I know Mado has included it on the RP tips page to be more detailed, but the fact of the matter is, I don't see it enough, so someone isn't paying enough attention and it needs to be said again. It's important that you include specifics about the way you're character is acting so the ref can respond accordingly. If you quietly walk into a room, it's different than if you burst loudly into the room which is different than if you stalk quietly into a room.
A bad sentence:
Epyon walks into the room
A good one:
Epyon, moving slowly and cautiously, opened the door and entered the room, eyes darting across the room to take in the scene before him.
The second sentence there gives a ref a lot more to work with in the response to your update. The first one gives him little to no reason to give you any details, as there's no evidence your character is taking any notice of them. You're probably not going to find anything hidden or cool by just walking around and into rooms.
On the polar end, you also don't want to include too much stuff, because it just become too much to read and uninteresting.
Set apart your thoughts, speech, and actions. Putting them together just pisses off and/or confuses your ref. Put your speech in quotes, "like so." Put your thoughts in italics, and just write out your actions.
A hugely important point that people don't seem to understand: you are not a god. You don't tell the ref what happens to anything other than yourself, and you can't assign feeling and points to other beings. You only know what you're thinking unless someone else tells you what they're thinking. Additionally, you can't just miraculously beat things up or destroy buildings, especially not at the beginning of the game. You can do anything, but whether you're successful or not is up to the ref and your stats.
When speaking to other players or NPCs, it's not fine and dandy to simply say that you talk to them. What do you say? How do you say it? It's not the job of a ref to define how your player interacts or to determine what information you're requesting; it's yours. You should clearly state your character's intentions and speech, preferably in quotations. You don't "just talk" to people in the real world; you communicate specifics and ideas. You have to specify what you want to know and what you're going to say and as an added bonus, maybe even the tone of voice you're using.