Hi Narlax, for about 30/40 quids, you can get a HOTAS (Hands On Throttle And Stick) like
this one.
This is I believe the first step (an essential one) into making your PC/Elite a proper simulator.
After a few hours of handling this toy you'd probably wonder how it was even possible to enjoy the game with a mouse & keyboard. I believe this set up is the perfect try out version, very good for the money, you can always upgrade it if you like it for something more
like this or this.
The idea is to bring all controls to the stick rather than ever reaching for your keyboard.
Once you're comfortable of doing so, and if this is not enough. You can always get your hand on a
Oculus Rift DK2 for complete immersion. Be aware though, you will lose quality as this is a piece of kit still in development, and you also will need a very powerful machine to run it smoothly. I do not own one myself and will wait for a finished version before even considering buying it.
If you think (like me) that the Oculus Rift is a bit over the top and unfinished, another good option yet still very immersive is a head tracking device like
TrackIr.
You can later think of
Rudder Pedals and the best piece of software for Elite (not essential but Oh My God so fun to use) if you fancy talking to your computer like Captain Kirk to his crew…
Voice Attack and a microphone.
I cannot see what else one would need.
It can quickly rack up in cash, and personally I'm quite happy with just the Thrustmaster Flight X Hotas, saving up for a better screen. But different people / different budget…
EDIT: what else? a comfy chair, 7.1 sound system...