There are two main approaches to choose from and both are valid:
1) You want to win! Daily chess allows opening databases (no engine analysis) and use of "analysis board" to see variations within that page (again no engine analysis) and clearly this element (different from live chess or OTB chess) is an advantage to those using these resources and similar at their disposal.
2) You would rather improve! You choose NOT to use analysis board for variations (calculate/visualize mentally instead to simulate OTB chess) and do NOT use an opening database. In this case, you may be at a disadvantage to someone using these resources, but your thought process will make the post-game analysis more meaningful and thought-provoking as you deeper analyze what lines you missed and why
p.s. This is one reason I don't like Daily chess much (correspondence format) because I prefer to think for myself and I realize this might put me at a disadvantage (option 2).
Whatever you choose, then good luck with that 
Personally, I mostly stick to live chess games on chess.com and am just more flexible with time control. I'd rather find the block of time for one or two longer rapid games than few minutes here or there for thinking and moving in Daily chess. I realize some like this format due to busy schedules, but the game flow changes and I prefer my games to be synchronous (one sitting, uninterrupted)
In Daily Chess, to use Opening Explorer or not to, see title.
At the moment I don't use any opening resources in my daily games, as can be seen by looking at them, and I've been agonising over whether to start or continue to wing it in every game.
I'm not unaware that my openings are dire to say the least, but I'm not keen on following other peoples moves even if this results in better performances.
So yeah, I've been mulling over this question for about a week and would appreciate your thoughts.