Interesting photos and remarks from a non-UK reader.
I would add :
Check lists : the ones in France / Belgium/ Germany are similar to those mentioned so far except we add :Radio on + correct frequency set.
and Airbrakes in and locked
I also add personally : nothing loose ( in cockpit ) after having had to return from a promising circuit because my bottle of water had rolled near the rudder pedals !
The FAI badges : for kids now : they had a value when 300 km in a wood and fabric open air cockpit machine really meant something extraordinary.
Today , Go to the Alps , hire an LS6 in a local club and you will make 300 Km in 5 hours and gain 3000m in a single day.
If you have money, hire an ASW22 and 500 K in 3,5 hours is feasable.
What does this proves : just that Germans build very ( very) good sailplanes and that Mountain waves are very good in the Alps.
Not that you are a better pilot.
Nowadays we are all in the Web : OLC ( on line contest ) or Netcoupe ( F) where we download our loggers and compare routes, circuits. altitudes chosen and times. There you can compare yourself and see who is the best pilot...or made the best choices and on which machine.
Doing 400 K one day where everybody else did 250 has not the same value , I can tell you, that showing off badges.