T18-CF3. If you look up "John Gammel" on youtube, you'll find some videos of SMD soldering that looks easy. And in fact, it IS that easy. He calls out the Hakko CF3 as "an amazing SMD soldering tip," and it is one of my favorites. The C means it is a hoof tip. The F means that it is tinned-face, only. The 3 is the diameter of the face in mm. You can also buy this style of tip in 1, 1.5, 2, and 2.5mm (The latter is in a "short" version, C
SF25. (I have them all, and the smaller ones are great for point to point jumper wires and such).
Another favorite of mine is the T18 K, knife tip. The claim to fame is that it holds a lot of solder and is sort of chisel-shaped, but it is angled so you don't have to position the board exactly just so to use it (twisting the iron changes the angle, unlike a chisel where the edge is always perpendicular when the blade is flat on the board), and it has a sharp point that can be used to pin components down while adjusting them with tweezers. Also, unlike a chisel, it is tinned on the working edge, only. Regular chisels have a tinnable surface extending up the shaft which is maybe useful for thru hole stuff. But just an extra hassle for SMD, IMO.
These are my most used tips, period. To round things out, I also sometimes use a regular bevel. T18-C2 and T18-C3 are the most useful, IMO.
It has literally been over a year since I used a conical tip for anything. Maybe 3 years since I tried a chisel. I do a lot of SMD soldering.
But don't forget the secret sauce. If you are going to solder any SMD, you will be wanting some liquid flux. MG Chemicals MG835 works fine to me. You can buy it in 125mL bottle or 1L bottles. Cheap as dirt. 100 packs of syringes and plastic tips are also cheap as dirt.
A knockoff tip assortment is fine to start. But there are several useful styles that won't come in this assortment. And once you find what you like, you owe it to yourself to buy genuine Hakko. They work better, and genuine T18 tips seemingly last forever.
Would use the finest tips possible for your iron
To each their own. I get the most mileage from the huger tips. CSF25, CF3, K. If you do a lot of bodge wire rework or protoboard stuff, maybe you will get more use out of the finer tips. Even here, I prefer the CF1/CF15/CF2 over the pointy conicals. Tinned-face-only tips and liquid flux make quick work of anything, really.