View properties with the auctioneer - it saves time because you don't get so lost, and you can determine boundaries etc on site
Spend time in the area you're interested in. If you're planning on living there year-round, see the house and land at its wettest and bleakest - in the winter.
Use a local solicitor - they know the other players involved and know when to push and when to hold back.
Remember that Dublin banks and building societies know little about the country property market - provide your mortgage advisor with auctioneers' listings of the area.
Provide your bank with builder's estimates and borrow enough for the renovations as part of the mortgage.
Try to buy where you already know someone, for advice on local builders etcetera and to help with feelings of isolation.
Check if planning permission has been granted for neighbouring sites.
Imagine how you'll feel if six Spanish-style bungalows are built in the neighbouring field in the next few years. Consider buying adjacent land now, to protect your privacy.