As Hallow said, the best strategy varies depending on the players, but here's my tips:
1. Block-hit. It functions as a sprint reset (similar to w-tap/s-tap, it can help you to combo other players), but A. your movement is more consistent, and B. you take less damage if you block while they hit.
2. Strafe. Alternating A and D can seriously help dodge others; straightlining is nice, of course, but the moment I started strafing I got 2x better at comboing people, and the combos tended to last longer as well (5-8 hits instead of 2-4). You can also try jumping occasionally, it can help throw off your opponent (and you get to deal more damage with criticals!)
3. Use projectiles. Personally, I prefer snowballs, but rods work well and even low-charged bows can help. Bowing a player back just before they get to you can help you to get the first hit on them (and is very useful for starting combos as well) because of the way ping works.