If you are fighting a Spanish army heavy in Jinettes (which they often are in early) I would recommend a starting army of (roughly) 4 spears, 4 archers, 2 swords (or MS), 2 cavalry.
-Put the spears in a half hexagon - two at the front and two at the sides at an angle with no gap.
-Put a unit of archers just behind each spear unit facing the same way.
-Cavalry and swords just behind to deal with flank attacks.
Dont break the formation until you have to. The Jinettes will get mauled by your archers (the horse is a big target and they have low armour)
Once you have destroyed / routed enough jinettes charge the centre with your spears and flank with swords and cavalry - the rest of the army will go pretty easily, especially if they have a lot of javelinmen which the Spaniards tend to use too many of.