possible ways to make bitcoin's usage safe

I use a deterministic wallet on my phone. I use Wallet32 but there are other deterministic wallets. I wrote down the 24 seed words on a piece of paper and keep the paper in a very safe secure secret place.

Now, I have a password on my phone to access my wallet. The wallet has cash in it. But, better than a normal cash in wallet scenario if I lose my phone then all I have to do is buy another phone, install the Wallet32 application, enter the 24 words from my backup and every Bitcoin address I have every used, every change address I have ever used, every transaction I have ever done is recovered "from the cloud" and "put back" into my new phone.

So a deterministic Bitcoin wallet on your phone is better than carrying cash in your wallet!

Also, you never have to back it up. All you have to do is keep a list of 24 words safe, secure and secret.

I think that is easy enough for just about anyone that is smart enough to own a smart phone.

yes this is interesting I am new and did not even know this was possible. All btc I have are on exchangers to avoid these problems. I am not a tech guy, only investor. So I understand the problems of common people with btc.

Having all your bitcoin on an exchange is probably the best way to have he greatest chances of having your coins stolen/lost. You are not only risking that the site owners run away with your money but you are also risking that your account gets hacked and your bitcoin withdrawn from your account.

I know but the exchanger is bitstamp, I set 2 steps authentication and control my account. Coins are still there. I am not a tech guy so I have fear to make some errors in keeping my btc by myself and lose. I asked help here in this forum but none explained my each step in detail.. they simply said "save in your hard drive" but I don't know how. Bitstamp seems quite professional to me. I have used it for long and always satisfied.

If you kept your bitcoin on an exchange then you would have the risk that the exchange were to run away with your bitcoin. 2FA is not going to protect you from this. Also the exchange's customer service may have lax policies for disabling 2FA and/or resetting passwords, potentially making it easy for an attacker to gain access to your account.

Yes, keeping your BTC on an exchange just gives you an additional layer of uncertainty and additional attack-vectors. Your Bitcoins are protrected by a regular private key, as well - still, you risk that the exchange goes bust, or actually robs your coins. You're in every case much safer holding those coins yourself!