As you may know, negotiating isn't for everyone. Many in business realize this fact but others don't. Those of us with a technical or artistic background may not make the best negotiators. This is unfortunate for those in the early part of their careers. It is during this time when you are your own best advocate so you will have to do your own negotiating. You don't have much experience and likely no formal training. Doubtless, your counterpart has much of both.
When you enter into a negotiating session, take a moment to evaluate the situation. Who is your counterpart? Much older and more successful than you? If so, you really should be prepared before your negotiating session. If you aren't ready, often the best tactic is to defer. This is especially true if you are caught off guard.
Say your boss calls you into his office and tells you to close the door. "Let's discuss your salary review now", he says. You thought that your annual review would be next month so you didn't really do any planning for this conversation. What do you do? You certainly want to hear what your boss has to say. Let him go first. Evaluate why he wants to discuss the matter early. Hopefully he just wants to reward you early because you are such a valued employee. Maybe he wants you to keep working hard now. Maybe there isn't any money for raises and the policy has just been given to your boss. Find out. By carefully listening, you may get some great information. Not just about your current salary, but the company in general.
You may be put on the spot in an unplanned negotiation. "What do you think would be fair at a difficult economic time like this?", you may be asked. How can you answer? Fair might be no raise at all. Maybe a pay cut. Maybe free overtime. There are possibly lots of options. The real answer is that the fair option now is the same as it always is - what's in it for you? That's it.
When you really aren't prepared to negotiate and you get put on the spot, you need to defer the session. Ask yourself what's in it for you. Maybe you just got offered improvements that work. If so, count yourself lucky and do the deal. If you didn't, you need to stop the session and start again when you are ready. "Well", you can say, "I thought we would discuss my salary increase next month". This is a strong response. He may have just said that there is no money, times are bad, people are being let go, they have to buy water with only one hydrogen atom now, whatever. "I would like to review what you said and look at my options". This would be a good time to reschedule. "Can we finish this tomorrow morning?" You need time to prepare but you want to get something finished.
With your position stated, you think you deserve a raise and you want to finish the negotiation the next day, (or as soon as possible), you can maintain a strong position. Now you can wait and listen, again, to what the response is. This gives you a chance to evaluate your counterpart again. If he persists, trying to get you to commit to a number, ask yourself why. Ask yourself, again, what's in it for you. At this point, it likely isn't good. Get out.
By deferring a surprise negotiating session to a time when you are better prepared, you can often be much more comfortable with the process. If you are comfortable, you will have a better negotiating experience. Each time you go through the process, the experience helps you get ready for the next one. Each negotiating session will be similar, in some respects to others that you have had. Listening to your counterpart and deferring to a better time will help you to increase "what's in it for you", and that is always the point to negotiating.