Hello and welcome @Danny_Dainton 
We add the ‘Before asking…’ snippet to our blocked Watched Words to encourage people to remove it before posting, which can work if it’s something small. We also use the <!-- Comment --> style ones Moin suggests in our plugin topics too, which has worked pretty well.
We also have a new ‘Topic Templates V2’ coming out soon, which may be able to help with this as well. It allows ‘form templates’ to be created, that also validate data before allowing a topic to be created. This may cut down the need on providing ‘text as structure’ from the outset.