I know this post is several months old, but thought I would respond with my own thoughts and ideas
Punishment of whatever type, be it corporal punishment, line writing, corner standing, naughty step. removal / denial of access to playthings and toys (including orgasm denial), early bed, etc. etc., does entirely depend upon the type of relationship you build with your little. Right from the outset of your relationship, you ought to lay out your individual wants and needs and expectations: what both of you hope to get from this relationship.
My first little girl ( I say first, rather grandly, I should perhaps say, my only little girl) enjoyed being spanked. In fact, that is how we met, over our mutual enjoyment of discipline, and that developed into enjoying pee play and watersports, which in turn, developed into a Dd/Lg/Dl relationship which turned out to be the most fulfilling experience of our lives! So in this case my Little was spanked often…. Not a hard terrible thrashing, mostly just an over the knee spanking with my hand, enough to make her bottom nicely pink, and herself, very aroused. Occasionally other instruments were used: hairbrush, paddle, strap and cane, these all hung in the nursery cupboard, and would be brought out as and when required. The original poster tried to draw the difference between punishment and what he called “funishment”. What I am suggesting that in a Daddy / Mummy / Little relationship, there is no such thing as punishment as such, as defined by the original poster, all discipline should be, what he calls” funishment”. A separation has to be drawn from Real Life, where we earn a living, pay taxes, vote, and partake in society and the economy, and the idealised fantasy life we indulge ourselves in: loving diapers and nappies, and being Daddies and Mummies to Little Ones. In this fantasy life everything ought to be fun and acceptable, for both parties
Now I know and understand that not all Littles have the same enjoyment of physical punishment, or any punishment for that matter, but there are times when discipline of some sort is required, so start out very mildly and gently, for whatever misdemeanour has occurred. Perhaps the removal of the bedtime story, restricting tv viewing, or no ice cream or sweets for a week. (Never take away the favourite teddy bear or soft toy, that to me is tantamount to ill-treatment!! ) From there work upwards, using your imagination. I soon discovered that, if you want an immediate promise of eternal good behaviour from your Little, the threat of no more orgasms or cummies, works absolute wonders!!