Hi im going help u on how to be a pro tinker,
lane:if ure using tinker, mid lane/solo is the best cause ur skill start off weak until u have lv 3 laser/rocketsalways solo if u can.
items build:bot and bottle is the most important stuff,
begining of the game buy a bottle go farm a boots,then make one bracer, and null taisman (cause it give fast mp regen,more mp and u will need it after u farm bot to make dagon)so after u got this 4 items(bot,bottle,bracer,null) go farm a dagon.after that u can upgrade ur dagon to lv 2 atleast idealy lv3, then farm guinsoo after guinsoo u can be owing, after that farm a dagger,then finish ur dagon to lv 5 and buy shiva.
combos:for me i like to use laser,atk,then rockets at early games,mid game when u have dagon, rockets,laser, atk or dagon depends on the enemy hp, late game after u get dagger and guinsoo use this combo rocket ,laser, dagon ,guinsoo , while the enemy turn to a chicken ,rearm use the combo again, and use dagger to chase ur enemy,or to give them a suprise atk when team battles.

tinker is a hero support hero for ur team, ur teleport wit bot is far better than furion, u can teleport rearm and teleport to base or where ever u want to go.
skill buids:
laser
rockets
march
laser
rocket
laser
rocket
laser
rockets
march
stat
march
stat
rearm
rearm
rearm
march
stat till 25
try to lv ur laser and rockets to max lv asap esspically laser