Use sharp sand and a little builders/soft sand

4:1:1 Sharp:Soft:Cement

Not too much water as they may float around when laid.

Make sure you wet them thoroughly after laying though for the next few days and no walking on them for as long as possible.

Point the joints with a strong

2:1:1 Soft:Sharp:Cement mortar mix

Again not too wet but wet once done and wet every day for the next week - especially important when the weather's hot.

Hi you use both. The mix is 4 sharp sand, 2 building sand, 1 cement,also put a bit of sbr bonding agent in.Keep the top surface of your flags minimum 150 mil below any damp courses and running away from your house if laying against your house.
good luck John

If you don't know this then get someone in who does, who knows how the patio will end up? I know nothing about computers so I wouldn't think about building one.

There's more to laying paving than simply the ratio and type of mortar mix. Ask 5 different paviours and you'll get 5 different methods, some use a little sharp sand to strengthen the mortar and some prefer soft only, depending of course on the type of slabs, substrate / ground and how it's been prepared.

Some applications / slabs / ground combinations don't require any mortar at all.

Don't forget the correct falls for all that surface water will you and the level below DPC and good luck with the cutting & pointing.

With sub again :) What about consistency of gear,correct falls etc?