You use Guard Up to make unblockable attacks blockable (max 1lvl of skill) and use Guard to reduce pushback from attacks (max 5 lvl of skill). I use a lot of Lance and HBG and just lvl 3 of Guard is usually enough. Chargeblade may need less since you can "charge" your shield (gives 1 lvl of Guard) and if you practice your timing, using guard points is like getting another extra Guard lvl (so from gear/decos, 1lvl of Guard is usually enough). IRC Lance in IB got "free" Guard Up as if you "charge guard" ( [R2] + (O) / [RT] + (B) ), then hold dodge ( (X) / (A) ) and wait for that bluish glow to appear (just be careful since it requires a moderate amount of stamina). Luckily, Shield deco won't be only-RNG dependent in 2 weeks (Fatalis update).