Don't fight the script. Embrace it, and make it your own.
Here are the two most common mistakes sales reps make during demos:
Going in with no script.
Sticking rigidly to the script, no matter what.
I know, most of us don't like scripts. But, gun to our heads, we all admit they serve some very important purposes: they keep us consistent, they make sure we say all the right things in the right manner and even the right order! They also give us flow: according to Gong.io, top-performing sales reps follow a process that mentions topics sequentially. Most of all though, they make sure we cover all the ground we need to. SEs put a LOT of work into these scripts, and for good reason.
However, this doesn’t mean we need to cling to that script like it’s the only thing saving us from falling off a cliff. This is where personalisation comes in. We don't want a rock solid, set-in-stone plan. We want playbooks, so we can run the plays we need, in the moment.
How To Personalize Scripts Like A Boss
Start with knowing your product inside out. Stay on top of new product features and releases, build relationships with product teams so you know what's coming up, and work closely with your SE to work out exactly how new features and functionalities fit into business use cases. However, there is a dark lining to this silver cloud… for me, personally, product expertise comes with a side helping of being an absolute bore. I go headlong into explaining every feature and functionality, and can get a little bit carried away from time to time.
Which brings me to keeping the room engaged. Top reps engage prospects every 8 minutes during demos, usually by asking engaging questions while they demo the product. This sort of in-line Q&A helps the prospect provide more in-depth responses. Never, ever interrupt your prospect - one, it's rude, and two, you're missing out on what they're trying to tell you! Even when you think you get it, wait, and let them finish. That's how you find out what really interests them.
Spend more time on things that interest your prospect. Which also means that you need to have the sort of fluency in your demo that doesn't depend on rigid structure. You should be able to go from A to E back to B if need be, and still not forget to touch upon C, D and F. How do you become fluent with your demo? Practice, practice, practice.
But What If It's A Custom Demo?
Ideally, you participate in demo creation: work with your SE closely, do run throughs, understand all the whys and wherefores of the tweaks and customisations done. However, in the real world, we rarely have the time or the opportunity to do so.
In a less than ideal world, you need a system. Think of ways that you can hold on to critical pointers and notes from discovery, and pass them on to your SE. Do you have processes that allow for inline comments from SEs, clueing you in on the changes/customisations they're making? If not, you should.
Also, look for ways to prompt yourself subtly, and ask the SE to work those into the demo. My SmartCue application does this beautifully - in context cues that you can add yourself if your SE doesn't have bandwidth, and it has the added advantage of letting you go off on a tangent and then return to the agenda, among its many, many smart features (It is a tool made by someone who has been a sales rep, and an SE, so…). However, you do you. Look around for tools that work for you, and your process.
Always Prepare For The Worst Case Scenario
Your SE is out, sick. Your prospect is late by a full 15 minutes for a 40 minute demo. Your screen froze, and it's staying that way.
There is so much that can go wrong in a demo that can mess with your flow and focus. I don't have solutions for every problem out there, but I do have Plan Bs for most. When prospects are late, I take them through the agenda and ask them what they'd like me to show them first. When my screen freezes, I turn it into a disco demo, because well, I can't show them anything. Might as well make the most of the time I have, so I can come back stronger. And if my SE is out sick, well… I use SmartCue and so do my SEs. So while them not being there shakes me a little, it isn't a showstopper because I have everything I need to do the demo myself.
Remember, calm confidence is the way to make a sale. No one trusts a sweaty guy.
Take It Apart, Later.
Feedback is how we get better at what we do. Schedule post demo huddles with your SE, and whoever else was in the room with you (include friendly clients here!), and really listen when they give feedback. Just be careful to fill the room with people who will give you constructive feedback, rather than folks who tend to be overtly critical or 'tough love' oriented. These folks hurt your confidence, which is the opposite of what you want.
Personally, I prefer to formalize these huddles, because most people prefer being polite and kind and you don't get true feedback when you just catch up with them after the demo. When it's a scheduled feedback session, it is easier for people to give you feedback without feeling like they're being critical or hurting your feelings.
You can also make the feedback process easier by creating a structure. Maybe use a rating sheet, or a questionnaire that allows people to rate/rank you. This way you can mark progress, while getting real, actionable intel on what you can do better.
Conclusion
You can prepare and memorize and plan and test and mitigate all risks… and still be blindsided. A strong sales rep isn't one who is never fazed by what's thrown at them, but one who recovers quickly and makes the best of what they've got. You don't have to be perfect, and you don't need to memorize a script to get it right. You just need to be the most confident, competent version of yourself and you need to grab every opportunity to learn and improve.
It'll take time and practice, but you'll get there. I did, and so did so many of my colleagues. It can be done. Someday soon, you'll be the boss rep who smoothly recovers from a frozen screen with a time-crunched grumpy client who didn't think you had anything to offer, to close the deal with the punchiest, most precise, most concise sales demo ever.
And guess what, you'll still learn something new the next day.