Writing spy and action stories, the training/background of the MC is important to give him/her credibility for their actions. I have done this in chapter one, but my first chapters are filled with action to hopefully motivate the reader to keep going. Adding character backgrounds seems to stifle the flow. Likewise, to explain the MC's skills and abilities in following chapters seems too late. Also, in the past, an agent often wants to read C1, and I prefer it to be an fast flowing read. I guess the basic question is whether to flesh out character's background early or not? Any ideas?
One technique you can use is to hint at background elements early on without fully fleshing them out. That way, when the time comes to bring out the exotic technical expertise, the mind-blowing computer wizardry, or the martial arts skills that would put Bruce Lee to shame, it will feel more natural when it's brought to the forefront. This can be as simple as an off-hand comment by a colleague or some other such bit of quick business. But by planting the idea early on (even though you are not going into any real detail at that point), it will not feel like you are pulling a rabbit out of a non-existent hat when the time comes for your hero to suddenly exhibit extraordinary skills.
don't give too much away before the POA otherwise a reader may think well I don't need to read any more allude to something significant in the characters background early on but don't make it blatant to early.
Seriously? If the character is a spy or other operative, the reader will readily accept that he or she has mad combat skills. In any case, the first time he or she uses those skills, the reader will accept that he or she was trained at some point. If your character is a pudgy middle-aged librarian, you may have to explain the skill after the event: Keep it lean and clean.
I agree, also you cant have action, action, action. It will get a bit too intense and at worse ultimately samey. Insert a moment of clarity and calm and within such a moment begin to sow the seeds of the MC's back story. Either through conversation, flashback or even journal entries if you must lol. We like back story, we understand they got skills but how is that little bit of extra sugar that sweetens the story. Plus its not just skills you can underline, but delve more into their psyche, why they became a spy or why they enjoy the killing or perhaps why they have an affinity with a certain gun. To paraphrase Sherk....Story's are like onions (and ogres)....they have layers. And when to tell us, drip feed us, keep us guessing. We know too much too soon the intrigue is lost, too little and we become frustrated.
What I do is add relevant things about the main character's background whenever it pops up, then I reread everything and take out the stuff that bogs down the story's flow. Some of the background information I've come up with will never see the light of day.
I would say keep some of the unused back story, you never know when it might be useful to resurface, say i a sequel if you desire.