Splitting Hairs Over Will And Would

Okay, would is the past tense of will and I don't have any problem using both as long as the tense is clear. Problem arises when using would in the present tense.

According to what I can gather from various online sources:

Will is used when the degree of certainty is higher;
Would is used to indicate a theoretical or tentative situation.

BBC has a brief but extensive explanation over the semantic difference between will, would as well as shall. It says:

3. Would (or the contracted form 'd) is sometimes used as an alternative to 'used to' when discussing past habits:

• 'When we were young, we would spend (we'd spend) every summer holiday at the sea-side.'
• 'You would find him (you'd find him) sitting at the bar every lunchtime, drinking that strong black beer and chatting to the bartender until one day he was there no longer.'

Would is also used to make polite requests:

• 'Would you be prepared to do all this work by yourself without any assistance?'
• 'Would you (be so kind as to) pick Jennifer up from school on Monday?'

Would (or its contracted form 'd in conversational English) is also associated with the conditional in its simple, progressive, perfect and passive aspects:

• 'There's no doubt about it. I would definitely (I'd definitely) travel to Mexico with you, if I could afford it.'
• 'You would still be (you'd still be) working for the World Bank, if you hadn't kicked up such a fuss.'
• 'I would have told you (I'd have told you) all about it, if you had phoned me.'
• 'If you wore smarter clothes, you would be invited (you'd be invited) to all the press conferences.' [BBC Learning English]
  

Thank God for BBC!

Here's another great resource for will/would usage in first, second and third conditional situation.