Compression fit joints

Hi guys just found this forum and boy am i glad you are here.

I have good general diy experience more in electrics than anything else and for the first time i am embarking on some plumbing work in the home ( installing a shower ).
I have never used compression fit joints to copper pipes before and have having a lot of trouble getting them to seal.
The main problem is when i tighten up one side of an elbow all is well but when i do the other i am having difficulty keeping the pipes steady and the first join either twists loose or I bend the pipe while i am tightening up also one and a quarter turns of the 22mm nut seems alot and when i get a third or so of the way round I seem to have to put a great deal of pressure on the spanner to get further round, this is the point at which either the pipe bends or things start working loose at the other end. Is there a special spanner or method of gripping the fitting to keep all still while i tighten up.
I am using a pipe cutter and deburring. One T piece and a couple of elbows is all I am fitting into the mains water supply.
Any tips on these fittings are well appreciated thanks.

If you're having that much difficulty is perfectly OK to tighten up one side without the other side inserted so that the olive clamps down on the pipe. Then slacken off a bit and do the other side. You can try supporting the elbow with some grips but you shouldn't really need to. The trick is to tighten up each side alternately in small incremental steps. You should not have to use that much force in 22mm, if you do, you'll just end up squashing the olive.

If all else fails, think about using hep20 - this always works.

Quite often the connection on to the shower if not supplied has to be a compression elbow as there is no room for a hep fitting.
Always support the body of the fitting when tightening up.
If you undertighten first go you can usually go back and nip it up later if it leaks.
Invest in a pair or two of waterpump pliers for tightening compression fittings. Worldwide tools and draper make cheap and cheerfull ones. any cheaper than that and you could expect them to fall apart in your hands.

Thanks guys for you replys, much appreciated.