The boyband, which consist of Merrygold, Oritsé Williams, JB Gill and Marvin Humes, kicked off their '4th Dimension' arena tour in Liverpool last night (March 14).
Merrygold told Metro: "I've got a couple of plans this year - I think the best is talcum powder on the pillow. If you've got a white pillow and you sprinkle talcum powder on it, you're not going to see it.
"They're just going to put their head down and half their face is covered in talcum powder. That's a funny one.
"This might sound a bit wrong but you get cheese strings or sliced cheese, lift up their mattress and put it under there or inside the pillows. They'll be like, 'What the hell is that?' but they won't find it."
When asked who he will be playing the practical jokes on, Merrygold said: "It depends who p*sses me off the most."
JLS have reportedly been banned from staying at hotels within a five-mile radius of their tour venues after their last tour had a number of incidents involving fans who caused thousands of pounds worth of damage.
> JLS behind the scenes on Team GB London 2012 promo - watch video
> JLS Aston Merrygold rescued by lifeguards on shoot
Watch JLS's 'Proud' music video below: