It's so tempting to plonk baby on the floor with all their toys within arms reach. Especially if, like mine, your baby gets loud and frustrated pretty quickly - sometimes I just want a minutes peace!
Whilst tempting to make it easy for baby or to put baby in a contraption like a exercaucer - it's better for them to be on their tummies and to have things to reach for! Things being that little bit out of reach promotes rolling, stretching, reaching and early crawling movements / scooting. It also promotes communication - remember that at this stage their crying is talking. If they cry out and look at Mum and then Mum comes to help, they're learning how to ask for help.
I like to put August in a play circle and watch, whilst offering words of encouragement. I don't go help straight away if he cries (though I'm desperate to) because i've learned that given time, he pushes himself just that little bit further and builds the resilience to keep trying.
Keep mixing up the toys so that your baby actually WANTS to move. Watch them carefully - some babies love the TV remote. Others love something shiny. You can put those favourite things just that little bit further!