You never want to be the one to engage the fight. So positioning behind or next to your support is important. Let others CC the enemy and take their aggro before you decide to move close enough to be in attack range.

Poke whenever you see the chance and last hit with your Q as much as possible to stack your passive.

Getting Level 2 first will have the biggest impact on your early lane. Smolder on Level 2 can be very threatening to most ADCs since his Q + W + Auto Attack deal a lot of damage in a very short time. It probably won't result in a kill, but builds enough pressure to be safe for the early lane.

It's important to keep your E at all times. It's an escape tool, not a DMG tool.

Once you have an item and unlocked your first part of the passive at 25, Laning will become easier. Even better at 125 stacks.

Number 1 rule for Smolder - Never go for a kill during lane unless the enemy has 30% HP or less.

Smolder is also a perfect champ to farm under your tower. Freezing the wave helps you reach higher levels faster and get stacks easier.

Why? Because, the less trades you take, the less you have to reset.

It's important to keep farming. Smolders passive never stops scaling. Even when you unlock the last part at 225 stacks, the DMG and the Area effect keeps growing. Especially the execute effect at 225 stacks since it starts executing sooner.

Stick close to your Support and only engage when another teammate takes the aggro or CCs the enemy. The longer you survive in a fight, the more valuable you are.

That's why your E is so important. It's the only tool you have to reposition fast.