What are the best practices in finding a mentor to edit and critique a pitch deck?

The best site for getting feedback on a pitch deck is Crowdsourcia.com. You can upload your draft (or polished version), then select from their pre-vetted experts and they will all collaborate on your pitch deck in real time. Check it out, first 10 comments are free too.

Hello, my name is Humberto Valle, I'm a strategic marketer with just about 10 years of service and partnerships with large global agencies.
I have pitched in the past and secured several rounds for a couple of our startups as well as helped others with feedback and training on pitches. feel free to send me your deck to humberto@unthink.me.

I too can review the deck briefly for you if you send it to me.

The pitch deck is really inconsequential though. It is the pitch (deck, appearance, personality, etc.) that matters.

So, please send me the deck, the intended tone/style of the pitch, and a list of who will attend (from your side), their roles in the company and their roles in the pitch.

Finding a mentor is long and complex process. What do you offer in return to a mentor spending time to review your pitch? Because there is no such thing as a FREE lunch, several years ago I have developed an entry level consulting service for my clients: pitchdeck review. http://www.anagard.com/services/InvestorPitchImprovement.html
Please check out my investor pitch review packages, chose that one that is the most appropriate for you and give me a call.

I have been working exclusively with startups and new businesses for over 5 years. This is my full time job (not a side gig) helping entrepreneurs get their business of the ground and get money from investors, so I have seen numerous pitchdecks and business models over the years. Because of that, I am not biased, I can give you probability of raising money with the current deck and work with you to fix the weak spots that everyone has. I look forward working with you.

Hire a specialist from one of the freelance marketplaces out there (Upwork is a good choice). I've been assisting clients with their pitch decks since 2005 and am an angel investor as well. I can take a look at your deck and offer suggestions for improvement. You can also check out some of our work with other startups at www.apitchdeck.com

Pitch Deck Building Blocks
What does the deck need to have in it? Your checklist should include the following topics:

1. Customer Problem: description of customer pain and how the company solves it - concept & key elements

2. Product Overview: what the company does, for whom and why it’s compelling

3. Key Players: founders, key team members, and key advisors, with industry backgrounds and expertise

4. Market Opportunity: market size, growth characteristics, segmentation

5. Competitive Landscape: competitors and competitive feature sets, plus your sustainable competitive advantages

6. Go-To-Market Strategy: how the company will sell its product, in detail, including roughly how much it will cost to build that sales engine

7. Stage of Development: product development, customer acquisition, partner relationships

8. Critical Risks & Challenges: what can go wrong and how the company plans to manage it

9. Financial Projections: how much time and money it will take to get to cash flow break-even and five year projections (it is really helpful if entrepreneurs show Yr5 mid-case, worst case and best case with key assumptions)

10. Exit Options: categories of likely buyers, rationales, list of specific likely buyers and comparables with valuation multiples

11. Funding Requirements: how much, what the company will use it for, what milestones it expects to hit

I am an expert in advising on pitch decks. Feel free to setup a call.