you can also seal with a hair butter in stead of oil (but most prefer oil I think). I use kinky curly perfectly polished after my leave-in. But I actually use more then just a few drops (and I have fine hair!). In the summer I use less oil then in winter time.
But if your hair is weighted down because of sealing (like some fine-haired curlies), you can also mix your leave-in with some oil and aply it all together (before your styler).