"Tactics is knowing what to do when there is something to do. Strategy is knowing what to do when there is nothing to do." -- Savielly Tartakower
What follow are the most salient features of the position that jump out at me, and these are the sorts of things one needs to look for when there seems to be nothing to do:
- You have no structural weaknesses yourself.
- Black has a weak backward pawn on the c-file that could become a very nice target.
- Black can attack down the semi-open b-file, but that's less significant since the move
b3 leaves White's pawn secure.
- At the moment, Black's bishop pair isn't of much use due to the relatively closed nature of the position.
Having noted those things, it's safe to say that Black would love to get in the freeing move
... c5, which would allow her to exchange off her most significant weakness, while also starting to open up the position for her bishops. So a good course of action for White here is to try and prevent that move from Black, or at the least to make it as disadvantageous for her as possible.
With that in mind, a good start is
1. Na4, which leaves both the knight and the Qc2 eyeing the c5 square (and opens the way for the rooks to bear down on it as well), and doing so with tempo thanks to the attack on the Qb6. After
1. ... Qb7 2. Rac1 Rfc8 (note: it's these rooks in particular because White might want his other rook being able to go to the d-file if
... c5 -> dxc5 occurs, and Black might want her other rook to have access to the b-file), we see Black trying to support the
... c5 break and White trying to stop it.
[fen "r4rk1/p2nbp1p/1qp1bpp1/3p4/3P4/2NBPN2/PPQ2PPP/R4RK1 w - - 0 1"]
1. Na4 Qb7 2. Rac1 Rfc8 3. Qe2 a5 4. Rfd1 c5 5. dxc5 Nxc5 6. Nxc5 Bxc5
In this case, Black cannot be prevented from achieving the desired pawn break, and so White will need to switch gears and find new goals. For instance, here
3. Qe2 (threatening
... a5 4. Rfd1 is a good idea (as mentioned before), so that we will be well-positioned after
dxc5, with our rook on the newly half-opened d-file pressuring Black's isolated pawn. For instance, play might proceed
4. ... c5 5. dxc5 Nxc5 6. Nxc5 Bxc5:
[fen "r1r3k1/1q3p1p/4bpp1/p1bp4/8/3BPN2/PP2QPPP/2RR2K1 w - - 0 1"]
Now Black's bishop pair is improved, but d4 is an inviting outpost for the white knight. If Black were to trade the dark bishop for the knight after it lands on d4, and we could recapture with a piece, then our structure and our bishop would be significantly better than Black's remaining one, and we would have good prospects for strong pressure against the isolated d-pawn. With that in mind, a good next step is
7. h3, which prevents Black playing
... Bg4 and trading off that bishop for our knight instead, and has the side benefit of creating luft for our king. Unfortunately for us, everything is basically level, as Black has ideas like playing
... d4 herself to open up her bishops and rid herself of her remaining weakness.
Anyway, I hope this gives you some idea of the kinds of thought processes that can be fruitful in "boring" positions like this one, the kinds of features that you should be thinking about when you're not calculating tactical possibilities (which you can never forget about!), and the sort of improvements that White could aim for from your initial position if Black were to fall asleep at the wheel.