Try Yusupov/Jussupow's 9 book training series and Nunn's Understanding Chess Endings. And some beginner warm up tactics then level appropriate tactics before your endgame or positional studies. You also have two types of advanced intermediates as far as openings go. Some memorize deep the theory (but don't fully understand the lines as this type of player sometimes doesn't play in the spirit of the openings) and others who just want to sit down and play a game of chess (usually playing things like the Veresov, Trompowsky, or London System).
Against the first type you may want a sound yet offbeat line to throw them off, or play a not so sharp but easy to remember opening. An example against the first is 1.e4,c5 2.Nf3,Nc6 3.d4,cxd4 4.Nxd4,Qb6!? (2...e6 works too but it's a different system, though transpositions between the two systems is possible) or 1.e4,c6 2.d4,Na6 fishing for Bxa6 Qa5+ Qxa6.
Miles plays some offbeat stuff:
Also memorize some offbeat lines from the KIA, Trompowsky, London, etc., as black that are both sound and feel natural for your style of playing. They'll still know the openings better than you but if you play memory for a little while they won't be the only ones to save some precious clock time
It is a far from complete training database I'm making, but it should serve as a nice sample (even with a potential novelty for white too)
I have been playing chess for about one and half year or so. I am struggling to pass 1600 mark on another chess server.
How should I prepare myself to cross 1700 goal? What should I study or practice regularly ?? I mean to say which area I need to focus on tactics, opening or endings??