Push fit water fittings are probably the easiest fittings to use and if installed correctly the fittings will be rated to 4 bar pressure. Below is a very brief video explaining how to use these fittings.
Do
Do heat the pipe before you push it on to the fitting
Do push the pipe on over all the barbs
Do install the pipe on or just below the surface
Do Not
Do not over heat the pipe
Do not install push fit fittings below the ground. Shallow installation is ok but deep installation is not advisable