I'll concur with much of the advice offered, especially;
1. The use of a decent pair of non-crush ratchet pipe cutters.
2. The use of inserts.
3. Ensure there is no strain on any fittings, especially near bends.
4.
www.pipestock.com for everything you need if you don't have a local stockist of pipe and fittings otherwise, use your local ag merchant for fittings.
5. Keep a range of connectors in stock as spares, for 'emergency' situations. If you've got them, you'll never need them. If you haven't, you'll wish you had!