None of these other methods will work. Even a person with the strongest willpower might one day want to sell their Bitcoin. That's why if you want to hold your Bitcoin long-term, send it to the wallet of someone you trust and agree not to get it back before a certain period. Another alternative is to send it to an address you created, store the key on a flash drive and put that drive somewhere you can't easily access. After a certain period, you can go there and get it back.
There's no other way. If your Bitcoin is somewhere you can reach easily, there's always a chance you won't be able to resist selling it.

It's good that you buy bitcoin with your extra cash after taking care of your basic needs and monthly expenses. Most newbies fail to understand this, and they use money for important purposes to buy bitcoin thinking to make profit in a short-term before the need of the money invested arises. You need to have a good financial management practice to be a long-term hodler, don't get carried away with little profit.

Holding Bitcoin for the long term without being tempted to sell is very difficult it requires a combination of mindset, strategy, and security measures to be able to hold for a very long period of time, below are some measures that will help you.

1. Backup funds.
Make sure you have an emergency, reserve and float funds, this funds will help you when ever you are in an emergency and you don't have finance which is what is needed, instead of dipping hands into your Bitcoin by selling it you can just use your backup funds to settle the emergency.
Having a backup funds will reduce the emotional pressure to sell during market downturns also.

2. Develop a Strong Conviction.
Understand that Bitcoin investment is one of the best investment right now in the world and holding Bitcoin for long term will be more profitable, and always remind yourself that Bitcoin is still growing and selling now means you have lost the future benefit of enjoying the big price.

3. Set a Clear Time Horizon.
Make up your mind and decide how many years you want to hold your Bitcoin if it is 5, 10 or 20 years, and tell yourself you will reach that time you have set for yourself, see your Bitcoin as an investment.

4. Surround Yourself with Like-Minded People.
Surrounding yourself with people who are also holding for long term are very helpful, since you are in this forum you can always visit thread where they discuss and encourage long term Bitcoin holding.

5. Stay Away from Daily Price Movements.
I'm not saying you shouldn't check the price movement of Bitcoin but don't do it daily to avoid being tempted, you may set a 10 years plan for holding and in the next 5 years you saw that Bitcoin has increased dramatically in price now seeing how big  your money is every day may tempt you to sell.
Check but once in a while.

6. Time-Locking Solutions.
Some platforms allow you to lock up Bitcoin for a specified period to prevent impulsive decisions.
This will really help you, when you have set out plan to hold for 10 years and you lock it for that 10 years you can only deposit more Bitcoin but  you cannot withdraw or sell it till that 10 years is over.

None of these other methods will work. Even a person with the strongest willpower might one day want to sell their Bitcoin. That's why if you want to hold your Bitcoin long-term, send it to the wallet of someone you trust and agree not to get it back before a certain period. Another alternative is to send it to an address you created, store the key on a flash drive and put that drive somewhere you can't easily access. After a certain period, you can go there and get it back.
There's no other way. If your Bitcoin is somewhere you can reach easily, there's always a chance you won't be able to resist selling it.

Having other source of income can make you hold bitcoin for long term and you will not be tempted to trade without long term holding, apply patient in your bitcoin holding is another method you can use to succeed in holding bitcoin for long term before you will be satisfy to trade to earn income because there is always an opportunity for those that hold bitcoin for long term to earn different income from the market,  using safe wallet to hold your bitcoin will allow you to hold for long term because you will not be thinking of scammers to have access to your coins because you know how safe or solid the wallet is for bitcoin holding before you chose the wallet, let two coin be your choice of holding, if bitcoin and altcoin is your choice, you will prefer to release altcoin when you have financial issues and continue holding your bitcoin for long term.

The best thing we can do is to forget that we are investing in Bitcoin and never check the market daily. Or let another person, a trusted person, manage to hold it rather than have it be in your control, so we don't have the chance to check it.

 We have to know that this is not an easy job, but it is going to be more about dedication and certainty to our goal. We don't just be like those people who say we will hold and forget what they say. Instead, we do what is necessary.

Having other source of income can make you hold bitcoin for long term and you will not be tempted to trade without long term holding, apply patient in your bitcoin holding is another method you can use to succeed in holding bitcoin for long term before you will be satisfy to trade to earn income because there is always an opportunity for those that hold bitcoin for long term to earn different income from the market,  using safe wallet to hold your bitcoin will allow you to hold for long term because you will not be thinking of scammers to have access to your coins because you know how safe or solid the wallet is for bitcoin holding before you chose the wallet, let two coin be your choice of holding, if bitcoin and altcoin is your choice, you will prefer to release altcoin when you have financial issues and continue holding your bitcoin for long term.