1. Love Jira. The main method of ensuring the team builds the right thing at the right time is a quality & well ordered backlog.
2. The team owns the stories and tickets. The tickets are just a tool for the team to manage the sheer volume of information and plans for what they want to build. If the team likes the tickets that's all that matters. Definition of ready should be defined by the team, bounce tickets that don't meet the standard.
3. Accept all approaches to engineering. You can nudge, discuss, encourage collaboration and best practice, and if anyone is way off then you should inform management, but in the end the tech lead isn't responsible for hiring and firing so work with and celebrate what you have, even if it's not how you'd do it.
4. Balance tech debt and maintenance with features sprint by sprint. Have a chore ticket every sprint for upgrades.
5. Fill in the gaps. Got a great product person then support them, if not then that's you and you need to bridge to the business.
6. Retrospectives are broken. Refocus them on what the team can improve instead of complaining about things that will never change.
7. It's all about relationships.
8. It's (also) all about sustainable & quality delivery of product increments.
9. Stay sharp, pick something to build or fix yourself that isn't on the critical path but makes life better for the team and the company and which keeps you intimately familiar with the technology.

"I will never love Jira."

Well it seems I accidentally created some clickbait on LinkedIn by mentioning jira there. To be clear my point is about having tickets refined, ordered and ready for the team just in time. I reference jira purely because that's what every client I've dealt with for years has used.

Like many others I also don't care much for Jira, but it let's me create and refine tickets with enough info, comments and attachments so what-evs. Other tools welcome too.

If the client/company has mandated jira then as a tech lead then you had better love being in there making it ship shape so the team can fly. It takes a good amount of a tech lead's time. All that time spent in jira solo, with the devs and with the product people is all well invested as it's a big enabler for the team to build the right things at the right time without being blocked waiting for tickets and requirements.

Ironically the better you are at this, the faster the team goes, and the quicker they are demanding more ready tickets!