Hi Chance -

As others have said, if you're wearing your kilt casually then a belt pouch or bum bag is fine, but if you're wearing any kind of top with pockets then you don't need either. I hardly ever wear a sporran when dressed casually and never when out hiking etc.

However, if you're dressing at all formally then a proper sporran is an essential part of the traditional wool kilt outfit.

Some like the feeling of security a sporran gives them, but in fact the benefit is more psychological than actual - any wind that is strong enough to "lift" a medium or heavier weight wool kilt is likely to lift the sporran with it (unless you've filled it with a couple of kilos of loose change or something!).