This is a common issue - youre doing an overhaul but don't want to disturb current business. Sure on Plus this is made easy ( If you are on plus, ask your MSM for a new dev shop and use the Transporter app ) but for non-plus stores, it can be a headache.
There's no cut and dry answer but here are some ways to get the job done.
- Create your dev theme and start doing your work there, as you're doing.
- For pages, as mentioned by drip's answer, don't link them and you should be fine. If you don't want search engines to index these while you're working on them, you can also add some liquid logic to your layout/theme.liquid and add the pages you don't want and have it add a meta no-index tag.
- If your products are being completely reformatted, i.e. new description formats and such, create one product that has the new formatting, then export your CSV and add the new formatting in there. If you do this, be sure to export again and update your inventory values in your newly formatted sheet since they have likely changed since your export and when your new product formatting is done.
- If you have new products you want to hide - give them a special product type, lets say hidden. In your smart collection rules - Type allows a 'not equal to' so set that there and also use the same no-index meta so google isn't indexing them until your ready.
Main things are - your new content can be 'live' in Shopify but if there's no where on site to link to it, its pretty safe unless someone guesses the url. then just make sure you add a band-aid so Google doesn't index them. This can also be extended to your sites search, a bit more work there but 100% doable.
The last bits that are 'always on' like your navigation - that you map all out and hustle on. Or make a new nav with a new handle and use that.
Best of luck! Have done many massive overhauls of sites and product data all while the site is live, just need to use a little finesse to work around some of the things specific to Shopify.
