I've recently been working on onboarding new players into 
1. Install Hive Keychain
To play Splinterlands, I think it's imperative to set up Hive Keychain. The Support team has a great article detailing exactly how to do that, so I won't repeat it here: https://support.splinterlands.com/hc/en-us/articles/4412500061588-Hive-Keychain-Installation-and-Usage.
2. Buy Hive and send it to your Hive wallet.
Hive is available on many Tier 1 and Tier 2 exchanges, including Binance, Upbit, Bitget, HTX, and can generally be fairly easily acquired.
After you do so, you can easily send it to yourself by simply putting in your username when sending it (e.g. in my case, "bravetofu"). No memo required.
This may feel foreign to those coming from most other big blockchains who expect addresses to look like 0xJk8Lb3... etc. But on Hive, addresses are human-readable names. Just another nice UX benefit of Hive.
You'll receive the Hive shortly (Hive has very fast transaction times) and will see it in your Keychain wallet.
3. Swap Within Keychain
Inside the Keychain wallet, you can directly do a swap to DEC. Simply press the "Swap" button.
Then select Hive as the currency on the top (that you're using to buy the DEC) and DEC as the currency on the bottom (that's what you're buying). Then press swap.
4. Find your DEC in Hive-Engine
Now, go to Hive Engine (personally I use https://tribaldex.com/) and log in with Keychain, then go to your wallet (i.e. https://tribaldex.com/wallet). Within a few seconds, you'll find your DEC there.
5. Transfer the DEC in-game
Now, go to Splinterlands and click on the DEC tab at the top, then on "Transfer".
Next, select "From: Hive Engine" and "To: In Game", and put in the quantity you want to transfer.
Click Transfer and approve the transaction with Keychain and within a few seconds your DEC will pop into the game and be usable in the various marketplaces (including of course PeakMonsters, my personal choice for all my buying/selling/renting activity in Splinterlands).
I hope this tutorial was useful. And btw while you're doing this, consider holding on to a little Hive along the way and powering that up in your Hive wallet :)
Vonak!
