As a solo traveller flights are important...if you have booked it all within a package deal then that is great but these tips still apply...if like me you can't help but book your flights yourself then make sure that you know what you want. For example; I knew that the first time I flew to the US I wanted to go with Virgin, It cost slightly more but that was a priority for me. This is the very first start of your trip if flying so you need to make sure that it gets off to a good start.
Once all your flights are booked I recommend that you take advantage of being able to check in online 24 hours earlier, if you can choose your seats before check in then take advantage of this too. Budget airlines have so many hoops to jump through for flights such as adding a bag will increase the price, then they will try to sell you insurance and such. Don't pay to reserve your seat on a budget flight, it is rarely worth the money, and you pretty much choose your seat anyway. If you are particular about this then make sure you get checked in, are at the boarding gate in plenty of time and are first on the plane. But don't forget that your route may not be that popular on that specific day or at that time and the opportunity to swap seats is likely to be available to you if some seats are empty after take off.