Any tips/suggestions to improve?

Get a chess coach for the fastest improvement, if you can afford it.

Otherwise you're sort of trying hard but may not see your weaknesses, and may be focusing on what pleases you more than what is best. Like trying to memorize opening moves but not fully understanding why the moves are good moves.

@lance5500 is a great coach, but if that's not your cup of tea, the coaches page has many.

Good luck!

For books, maybe look at Coach Yourself, Training for the Tournament Player, and Chess Training For Budding Champions. Build Your Chess series is great, as is the Steps series.

Ultimately it is hard work that helps most. There's no shortcuts.

Edit: and it will take a very long time to get very strong, so enjoy the ride :)

1. Develop your pieces quickly.
2. Control the center.
3. Put your pieces on squares that give them maximum space.
4. Try to develop your knights towards the center.
5. A knight on the rim is dim.
6. Don’t take unnecessary chances.
7. Play aggressive.
8. Calculate forced moves first.
9. Always ask yourself, “Can he put me in check or win a piece?”
10. Have a plan. Every move should have a purpose.
11. Assume your opponent’s move is his best move.
12. Ask yourself, “Why did he move there?” after each move.
13. Play for the initiative and controlling the board.
14. If you must lose a piece, get something for it if you can.
15. When behind, exchange pawns. When ahead, exchange pieces.
16. If you are losing, don’t give up fighting. Look for counter-play.
17. Don’t play unsound moves unless you are losing badly.
18. Don’t sacrifice a piece without good reason.
19. If you are in doubt of an opponent’s sacrifice, accept it.
20. Attack with more that just one or two pieces.
21. Do not make careless pawn moves. They cannot move back.
22. Do not block in your bishops.
23. Bishops of opposite colors have the greatest chance of drawing.
24. Try not to move the same piece twice or more times in a row.
25. Exchange pieces if it helps your development.
26. Don’t bring your queen out early.
27. Castle soon to protect your king and develop your rook.
28. Develop rooks to open files.
29. Put rooks behind passed pawns.
30. Study rook endgames. They are the most common endgames.
31. Don’t let your king get caught in the center.
32. Don’t castle if it brings your king into greater danger.
33. After castling, keep a good pawn formation around your king.
34. If you only have one bishop, put your pawns on its opposite color.
35. Trade pawns pieces when ahead in material or when under attack.
36. If cramped, free your game by exchanging material.
37. If your opponent is cramped, don’t let him get any freeing
38. Study openings you are comfortable with.
39. Play over entire games, not just the opening.
40. Blitz chess is helpful in recognizing chess patterns. Play often.
41. Study annotated games and try to guess each move.
42. Stick with just a few openings with White, and a few openings with
43. Record your games and go over them, especially the games you lost.
44. Show your games to higher rated opponents and get feedback from
45. Use chess computers and databases to help you study and play
46. Everyone blunders. The champions just blunder less often.
47. When it is not your move, look for tactics and combinations.
48. Try to double rooks or double rook and queen on open files.
49. Always ask yourself, “Does my next move overlook something
50. Don’t make your own plans without the exclusion of the opponent’s
51. Watch out for captures by retreat of an opponent’s piece.
52. Do not focus on one sector of the board. View the whole board.
53. Write down your move first before making that move if it helps.
54. Try to solve chess puzzles with diagrams from books and magazines.
55. It is less likely that an opponent is prepared for off-beat openings.
56. Recognize transposition of moves from main-line play.
57. Watch your time and avoid time trouble.
58. Bishops are worth more than knights except when they are pinned
59. A knight works better with a bishop than another knight.
60. It is usually a good idea to trade down into a pawn up endgame.
61. Have confidence in your game.
62. Play in as many rated events as you can.
63. Try not to look at your opponent’s rating until after the game.
64. Always play for a win.

Credit: 700 Opening Traps by Bill Wall


15. When behind, exchange pawns. When ahead, exchange pieces.

What does it mean please? behind = losing ; ahead = winning?

Get a “chess tactics pro” app on your phone and solve the 250 free puzzles, then do them all again. And again. If you pay a few dollars they have 3000 puzzles. Another phone option is CT art, they have apps for beginners with tactics and lessons on strategy etc.

For a book Polgar’s World champions guide to chess is a good start. After that you can do a Silman book like Ameteurs mind or Reassess your chess.

Basically solve thousands of puzzles many times over, and read a few books, that alone takes you to 2100 and above.

Structure your chess training around solving as many tactical/strategic puzzles over the board as you can. If you're planning on playing in a real tournament it is very important to do most of your work on a real board. You will make mistakes on a 3D board that you normally wouldn't on a 2D board, being that you only train online. GM Naroditsky gave good advice in a video he did years ago: Play only a couple games online a day! I wholeheartedly agree with this advice even though I don't follow it. My biggest chess gains have been during times where my online playing is limited and OTB training games with partners of like-strength are frequent. Also, if you're super serious about improving, start slow. Don't burn yourself out with some Kamsky-father-son-like eight-hour training regimen. I'd recommend solving tactics for an hour, play a couple games online, preferably over 10 minutes and with an increment. If you love playing 5 minute games, I'm not going to tell you to stop. The key ingredient in the recipe for NOT burning out, is to enjoy yourself. Then do an hour of endgame training. I'd recommend playing through the examples in Mikhail Shereshevsky's Endgame Strategy, on a real chess board. As for problem solving, too many solid recommendations to name. Zenon Franco's 1001 Puzzles comes to mind, get in on Kindle for cheap! Happy hunting.

Ignore all the advice, however good it is or may be.
If you want to improve, play, play, play and then play some more, if you get battered by an opponent check the analysis on Lichess.
Very few people will ever reach GM, so just be patient, play, play and play some more and when you get beaten by a lower rated player analize your game.
If you really want to get to 1900+, then by all means, get a coach, read books, study games and spend 4 hours a day playing, but if you simply want to improve then just PLAY as much as you can - all depends on your actual goal, do you want to improve or do you want to be a GM/IM/CM etc?