Minecraft Allocating more RAM issue

I only have 200 - 250M of Ram for Minecraft. So, I look up How to Allocate More, But Every tutorial, Every JVM Memory Error fix, Etc. And still, Nothing. I'm always Left with 200M of Ram for Minecraft. I hope to get this done ASAP. I've started my Minecraft Channel, And I always Crash Minecraft And/or Get Lag Spikes of Death. In fact, when I went to get a Picture of my RAM, Java Automatically Crashed with the "Out of Memory" Error. I can Hardly Play Minecraft with this little RAM. So please, if Anyone knows how to Fix this, Please Tell me!