You might want to check out AA9PW's website - in the cw practice section, very bottom, there's a QSO generator. You can set speed and Farnsworth timing to what you 'get' (or 20% over if you want to challenge yourself) and it will generate nice 'standard type' QSOs. That's helpful because as others have said here, when you fall off the rails, you'll hear the beginning of a phrase or section you expect and be able to resume copying. Seiuchy (sp?) is a site / standalone script thing you can web access or do offline via e.g. your phone, it also has a full QSO generator with other options (e.g. simulate sending problems with descriptive titles like 'straight key horror'). I blame / credit AA9PW for the format and content of my usual CW exchanges to new contacts - I liked the order and content in those examples and got in the habit of emulating it. (On a weaker or not yet known RST situation, I usually BK after name/QTH/RST to find how other station is copying, then carry on with the rest of the stuff) All of that goes out the window for me when it's not my first QSO with someone - QSO usually more freeform then since we already know each other's QTH etc.