When buying a new mattress it is important to look after it properly to prolong its lifespan. Some basic things you may already be aware of are not to jump up and down on the mattress like a trampoline and not to bend the mattress as this can damage its structural integrity.
Turning your mattress once a week from purchase will help the fillings settle into place, after doing this a few times it will only become neccessary to turn the mattress once a month. It is also important to use a breathable mattress protector as non-breathable protectors can cause the mattress to condensate.
It is good practice to regularly use a soft brush to brush down any dust and fluff from the mattress and never use a vacuum cleaner. Stains and spillages should be absorbed using a dry cloth or household paper towel products. Sponging with a damp cloth and mild solution of soap and water may also help lift some stains.