I'm trying to make an enchanted-appearing item in my mod, like the potions in the vanilla Minecraft, but I cannot figure out how to make my non-enchanted item look like it is enchanted.

If I understand what you mean this is what you need

 

    @SideOnly(Side.CLIENT)
    public boolean hasEffect(ItemStack par1ItemStack)
    {
        return true;
    }

It worked- thanks!