How do you design a pitch deck: whether you invite a designer, use a template, or assemble a design

You should take it as far as you can yourself and if you really feel the need get a designer in. I've designed many decks and always make sure the text is easily editable by the client. There's a fairly standard 10 slide structure these days of what's needed.

Usually do pitch decks myself. I find the fastest way is first to dump thoughts and rough layouts and improve iteratively over time.

You just do it yourself! You need 5 pages, and no designer is required for it.

Here's the way it should be done — 1. Get the outline of the content ready for all the slides in google doc or google slides. 2. Define the goal of the pitch deck. What are you trying to achieve. 3. Define the segmentation of audience who is going to be seeing it. 4. Define what kind of feeling you would like to invoke of your brand through the presentation — Serious, fun, premium, elegant, authoritative, startup, etc 5. When you define the outline of the content, also highlight the priority and context of it. 6. Make this solid document and give it to the designer along with your brand assets if you have any or ask designer to create the visual personality for the same. 7. Find the designer on internet or subscribe to craftemo.com ;) 8. Let the designer do the magic. Hope this helps. Disclaimer: I'm the founder of craftemo.com (A web & product design on subscription service) and we are launching soon on PH.