I see fire and brimstone preaching as getting people to convert by fear, teaching them that the reason is not love but fear of going to hell. Using this fear to control people and their actions would also fall under this, focusing on the bad things too much, how horrible of an eternal damnation you will have if you make the wrong choice.

Modern day versions of this are not usually like puritanical preaching. I once saw a billboard on the side of the road that said "Go to church or the devil will get you" or something like that. Chick tracts abound, I've walked into various denominations of churches and seen them on a table displayed. I've seen those hugely popular tv preachers give sermons I would call fire and brimstone.

I have not seen it much in churches but I tend to avoid going to churches where I think I will see this or going to them more than once.