they/them/their, with your favourite language reform. (I'm partial to ‘singular conjugations with singular pronouns’, myself.)

Whatever is clearer to your intended audience (e.g. what best reduces grammatical ambiguity). As a tie-breaker, whatever you think will best erode the gendering of English third-person personal pronouns.

I like tools. Tools exist to serve a purpose; good tools serve many purposes. The purposes are the important part – but I'm no good at solving problems. I hope my tools will be enough.

Testimonials from satisfied costumers:
• "this pun is so fucking bad and i hate you for it" — @miko

If I'm doing wrong, please tell me. Either I don't know (and you've saved everyone a lot of grief), or I do know (and I should face consequences).