At the start you can buy 2 of your 3 items and you need 5 gold more to buy the last one so after buying 2 you head to bot and start by placeing 3 traps when thats done you go back to buy the last item.

At the start if the enemys are good harrasser you can chose to go with 2 points in heal for lvl 2 and 3 otherwise I always go with spear since 2 spears can knock them down to 1/10 of health makeing them easy targets.

If you faceoff against supporter like taric/leona/blitz take care to never get in their range untill they have 2-3/10 of life left remeber your spear of the longest range so there is no need to in to theirs because you auto do so little damage.

Make them fear the spear but dont trow it every time it gets of colddown or they get used to the pace.