To Instruct Or Not To Instruct

When writing a script, how much direction do you put into it?

I ask because I've heard a whole bunch of answers...

1. Never, ever put in camera directions
2. Only add camera instructions when you're heading into production
3. Use them sparingly -- only when absolutely necessary

and finally...

4. Why the hell are you even asking? Of course you need them!

So, which answer is right? I tend to follow #3. I may be completely and utterly wrong since I'm such a newbie, but here are my reasons...

1. I want my script to read well. This is especially important when you're trying to sell something. I don't want anyone reading my script caught up in camera instructions. I want the story to be front and center.

2. I have an inkling of what it's like to be a director. If I'm lucky enough to ever have anything I've written go into production, I think I'll let the director do his job. They know what they're doing. On the other hand, would some directors find a whole shwack of instructions useful? I have no clue.

3. Although I've been through a fair amount of training in film, I'm not an expert. I'm just writing the script. The people who are experts know their jobs well. See #2. Also, I don't want to somehow make myself look like a dork.

(I once read on Alex Levine's blog on the Stargate web site -- I think it was his -- that they once received a script from someone who put their spec on multi coloured paper to try and make it look 'professional'. It just made said person look stupid. Now, I really don't think I'm stupid enough -- or uneducated enough -- to make a snafu of that level, but who knows... it could happen!)

So, am I wrong? I've always wondered what I should do. Should I give more instructions? Should I not? Is it a personal choice? To be honest, I have no clue.