The easiest place to start is with a 'construction in progress' account that lists all the amounts spent when they are spent. This accumulates all the costs for analysis once the construction is complete.
Once all the work is done, these amounts can be transferred to 'leasehold improvements' and depreciation can start. Any items that do not qualify can be reclassified then.
Now to the costs that likely qualify.
architect fees qualify
permit fees do too
construction costs all qualify
equipment might be a leasehold or simply an equipment purchase. the test has long been if the item is attached to the building, then it might be a leasehold. standalone equipment is not. also, if the landlord expects to keep the item after the lease is done, or if you expect to abandon it, then it is a leasehold.
add to that any legal or professional costs you might have in the lease creation, asset classification, or other behind the scenes professional work like tax lives, etc.
That seems like a good list to start from. If this covers all your questions, please leave positive feedback on our five star scale so i am credited with responding. If you need specifics, please ask.