First find what type of staking you want to do (boxing, mage boxing, range boxing, armor on melee) Mage boxing your going to need to level your mage to 99 and get your con/def high for whatever levels your going to mage box against. For boxing your going to want your defence and attack +15-20 levels higher than your strength. Range boxing I believe is better to have high con than high range. Armor on melee just relies on you being able to afford torva/stat get your attack/defence a bit higher than strength for armor on.
To all the people saying make it into a max pure, don't. Most people will not want to ever duel a 113 with a staker like name and if you make it to a normal looking name (something like cowman561) they are just going to highscore search you and not want to duel. Your going to go against other maxed stakers which really only gives you 50:50 odds, you might be able to stake a few people almost maxed that have a slighly lower defence. It is a lot easier to make an unmaxed staker in the 95-105 cb range, this way you can set the odds in your favor and win the majority of the time.