Activate Woe Strider by sacrificing Boros Garrison.
When Boros Garrison dies, Toph, Hardheaded Teach triggers, returning Boros Garrison from your graveyard to the battlefield tapped.
When Boros Garrison enters, it triggers, returning the artifact cast in step 1 from the battlefield to your hand, as it's a land due to Toph, the First Metalbender.
Resolve the Woe Strider ability
Repeat.
This clever loop turns your nontoken artifacts into lands thanks to Toph, the First Metalbender, allowing Boros Garrison's land-bouncing entry trigger to continuously reclaim a zero-mana artifact from the battlefield. Every time you cast and bounce that artifact, Toph, Hardheaded Teacher triggers to earthbend your lands while Woe Strider stands ready to sacrifice the animated Boros Garrison for scry utility and death triggers. Because Boros Garrison is treated as a land by Toph, the First Metalbender, its death reliably cycles it back through your graveyard to fuel Woe Strider's sacrifice loop and repeat the entire sequence.