These are all the rage down here at the mom. :mad2:
My advice would be as others have said ckeck substrate for flatness first, use a 12-15mm notched trowel, when fixing only fix 1
tile at a time postion yourself in the direction your laying your rows and work with the row, don;t be tempted to glue a row and start fixing across yourself, your back and arms won't last the distance, use a square edged timber block to wipe over your joins if it catches anywhere along the joint there is lipping and adjustments will need to be made.
Allow youself to lay between 5-7m2 per day and at least 3 days to grout then polish then seal, DON'T SEAL BEFORE GROUTING. Use a 3mm spacing and grout with a non sanded smooth grout that blends well with the colour of the
tile, because they are quite thick sometimes you need to grout over the tiles twice to get a nice full joint allowing the grout to get quite stiff between wipes.
Also use a good quality non-slump floor adhesive i use ardex sts8 for these tiles.