If your DJ has asked you for a playlist remember it is your personal choice. The DJ should have met you but not perhaps your guests. If you are unsure just say. A good DJ will always offer some choice if only to be polite but should have a wealth of experience.
More often than not I find most people really don't quite know. A skilled DJ can usually read the floor quite well on the night. That is their job.
A few pointers beforehand can be helpful to a DJ to fit in through the night if the dancefloor begins to thin.
To make an evening go well the DJ needs to be beatmixing so it flows and quite often matching tunes in the same musical key so quite often long playlists in advance can actually hamper the DJ especially if they have to be played in order.
I made a HUGE playlist of our favourite songs and gave it to our DJ, and split them into sections for before dinner drinks, during the meal, and later on for dancing (he added his own later on too)
I can email you it if you like but our type of music might not be your taste
Could you send it to me please - it would be greatly appreciated - [email protected]