When we had a greengrocery shop we always pressed the end of melons with two thumbs, if the melon "gives" then you are OK.
When my late husband grew melons one year he put nets round the melons when they got to a certain size, the nets were then tied to the framework . I am having a go at growing them this year.. I have a very Large roll of this netting stuff, comes in handy for all sorts of jobs!!!