I don't have any great answers, but I'll share how I think about this:
I have a cold storage wallet in which I have mixed coins and unmixed coins. This is probably not ideal, but I label and use coin control, so I feel okay with it.
I have an assortment of utxo sizes. I'm hoping that when I need to spend from this wallet, I'll be able to find a single utxo that is close to what is needed and then I will spend only that utxo and mix[1] the change.
My only suggestion is that if you've already consolidated CoinJoined UTXOs in your cold wallet, don't mess with them until you actually need to spend them. It carries the risk that fees will be higher in the future when you do need to mix them or something, but I don't think this risk is much greater than the possibility that payjoins or some other privacy preserving tools are developed.
I doubt my thoughts are very helpful here, though. It's a hard problem to solve.
I am quite a fan of Darth's suggestions about using lightning to get privacy. Receiving to a channel, then spending to a different lightning wallet and atomic swapping to the chain is not a bad way to mix. ↩
I don't have any great answers, but I'll share how I think about this:
I have a cold storage wallet in which I have mixed coins and unmixed coins. This is probably not ideal, but I label and use coin control, so I feel okay with it.
I have an assortment of utxo sizes. I'm hoping that when I need to spend from this wallet, I'll be able to find a single utxo that is close to what is needed and then I will spend only that utxo and mix[1] the change.
My only suggestion is that if you've already consolidated CoinJoined UTXOs in your cold wallet, don't mess with them until you actually need to spend them. It carries the risk that fees will be higher in the future when you do need to mix them or something, but I don't think this risk is much greater than the possibility that payjoins or some other privacy preserving tools are developed.
I doubt my thoughts are very helpful here, though. It's a hard problem to solve.
I am quite a fan of Darth's suggestions about using lightning to get privacy. Receiving to a channel, then spending to a different lightning wallet and atomic swapping to the chain is not a bad way to mix. ↩