One of the issues that I have at the game table, when I am not GMing, is that I tend to be quiet. While this isn't the truth in every game - I'm better in small games - and I have been working to fix it, it is still an issue. Even when I play louder characters, I'll tend to tone them down as the game goes on and take more of a second or third row role in the game. The reasoning behind this, at least on the surface, is simple: I don't want to cut into someone else's time in the spotlight. That also means that this post is for me as much as it is for anyone, but I still want to talk about it.
It's Ok To Have The Spotlight
The big thing that quiet players need to understand is that it is perfectly fine for them to have the spotlight. A good GM will give you time in the light anyhow, but you need to be ready for it. Being ready for it means accepting that you having time as the focus is not only ok but something that you deserve. When the GM looks at you and asks what you're doing, say something. Do something. Take your moment and live it. Share it if that makes sense for the character, but do something with it.
The problem here is accepting that "you deserve this" aspect of the advice. Sure, you can logically know it, but that doesn't mean it is something you will accept. Go with baby steps if you're not sure how it feels. Do one thing, something small, that involves your character getting GM focus. Work up from there. The game isn't going to fall apart.
Trust The GM
Ultimately the GM is the one who is responsible for handling/scheduling screen time; not you. So trust them to do their job. If you want to do something, tell them. If they're busy, pass them a note or wait for a chance to slip it in. Trust the GM to make sure everyone gets an even shot at time in the spotlight. If you want to help the GM, don't do it by backing into the shadows but rather by pulling someone else with you into the light. If you see a player just kind of tagging along, grab them and do something. Bring them into the light and let them get some of that attention. If you're getting too much, the GM can tell you to wait a bit, but as a player you have a more direct way of getting a quiet player involved with the game while simultaneously not leaving them alone in the spot light.
Trust The Players
Role playing is a weird thing. You are pretending to be someone other than you are. In real life you're an under appreciated IT worker, in the game you're a 6'6 barbarian with a giant sword. In real life your friend might be a very loud atheist, but in game they could be playing one of the most religious characters you've ever seen. Both of those don't even come close to touching on the people who are gender bending or portraying character types they have no experience with. The point is, everyone is out there acting silly, so why feel so weird about doing it yourself?
I bring this up as a lot of people I've spoken to over the years have mentioned 'stage fright' as the reason why they're quieter at the game table. it feels weird acting these things out in front of friends. Maybe even weirder if you're playing a character that borders on something risky or otherwise out there - and everyone has limits in weird places, so be aware of that.
However, the thing to keep in mind is that everyone at the table is doing that. So, trust your fellow gamers to be ok with it. Go out there and play your character, show them what makes your character tick and make them react to you. These games are at their best when everyone is out there throwing stuff into the pot, so go ahead and throw your own brand of spices and plot turns into the fray.
As I've said, this post is ultimately for me as much as everyone. Amusing considering how out there I can be that I'll have issues when actually playing in an RPG. Still, everyone has their own take, so what advice do you have for yourself and/or the other countless players that tend to take that step back and leave the spotlight to everyone else?