Screws
Have to agree about the Spax screws, they're infinitely better than any other screws I've ever used, just seem to suck themselves into the wood, Just make sure you get the right posidrive head (like a Phillips head) for the screw, each box has a code like PZ1 on it to indicate the driver head to use, and get a good one of those too. Buy them from a builders merchants and tell them you want the trade price, ignore the first price they quote you.