Thought I'd write up some Blackship tips for you folks.
You'll already be familiar with how Amazon often sends the same order as multiple packages. This is going to cost you due to the $1 receiving fee per package, and a further $3 to later open it and consolidate the contents into the final package to send out to you. It's impossible to predict how many packages, so if Amazon is only slightly cheaper than say Factory Gear on something, you may be better off going with FG. On my last order I paid $3 extra to Amazon for "fewer trips" on my order hoping this would avoid this whole problem, but they just delivered the same number of packages in one consignment rather than spread out over several days - which did not help.
They seem to play it safe with bubble wrap to make sure your stuff arrives undamaged, but this does increase the size of the package and isn't really necessary for most tools. On my last order I put in a notes entry to say minimal bubble wrap please, and they seemed to have followed my request. Anyway with the shipping estimator, it seems that it's weight rather than size that determines the price, so it might not matter so much.
You can estimate shipping here (
https://app.blackship.com/shipping-calculator). Also when each package is received you get a photo of it, with measured dimensions and weight. Note there is a sea mail option which is much cheaper if you want heavy metal stuff - I might try this sometime.
I haven't used these, but once a package is received you have a couple of options before shipping it. You can request a photo of the contents, request to split it up, or even dispose of it. I guess these may come in useful if you want to check on something important, or get rid of something unexpectedly heavy or bulky that isn't worth getting shipped out, or ship items using different services depending on size/weight or urgency.
The processing wait time is 2-4 days now. It was 16 days a few months ago, so I paid $5 to expedite.
The most tedious thing is filling in the customs info for the contents of each incoming package. You need to select the type of each item, value, and country of origin. There's an autocomplete for item types and common items, you can either find the item here (or something close enough), or submit a proposal for a new item (I never have). You can do this from the time any package is received, to avoid leaving yourself a big bureaucratic task until the end.
I have not tried shipping out bladed items, liquids, or batteries. Some of the items will ask you to specify whether it contains a battery, magnet, or (oddly) fabric. I wondered if these might risk triggering some additional customs attention and procedures, with associated fees.
There's 45 days of free storage for each package, then daily fees (not unreasonable). I've not ordered anything I imminently need from Japan, so what I do is place some orders, wait a couple of weeks until I think of or remember something else, so I have a chance to add them.
If you order from a local store and they contact you the email will be in Japanese, and might go to your spam folder.