Quote
Blockchair
Don't send round numbers
Don't send round amounts. Instead of sending 0.1 BTC, send 0.10125
Use Bitcoin Mixers
Mixers add an additional layer of privacy to a transaction to avoid exposing user identities.
Avoid reusing wallets
Don't send your Bitcoin change to the same address you use for sending bitcoins.
Avoid including many of your addresses in one transaction
Any time you can, try not to send BTC from your various Bitcoin addresses.
Avoid using "send everything" option
If you are withdrawing funds from an exchange, it is okay.
If you're moving funds to another wallet, do not transfer the whole amount to another address. It greatly compromises your privacy.
Don't send round numbers
Don't send round amounts. Instead of sending 0.1 BTC, send 0.10125
Use Bitcoin Mixers
Mixers add an additional layer of privacy to a transaction to avoid exposing user identities.
Avoid reusing wallets
Don't send your Bitcoin change to the same address you use for sending bitcoins.
Avoid including many of your addresses in one transaction
Any time you can, try not to send BTC from your various Bitcoin addresses.
Avoid using "send everything" option
If you are withdrawing funds from an exchange, it is okay.
If you're moving funds to another wallet, do not transfer the whole amount to another address. It greatly compromises your privacy.
I transferred all my Bitcoin in a particular wallet to another wallet and I noticed my privacy score was 60%. I decided to see why it was that low. Blockchair gave the above guidelines but I'm more focused on the last point. The reason was that I used the "send everything" option. Blockchair said, "It greatly compromises your privacy". I decided to do further research to understand why this was so.
I couldn't find anything convincing but I found out that using the "send everything" option or "max" in some cases, reveals your entire Bitcoin holdings and it's true. But I still don't know how others will know that's your entire Bitcoin holding without the private key.
Also, it's inadvisable in case of a mistake. If you mistakingly send Bitcoin to the wrong address holding if you use the "send everything" option you could lose everything in that address.
I don't know who this can be useful to but I just decided to share just in case, and I'll also want to know if there are other security or privacy risks in transferring everything out of an address at once.