Which are the factors that define slippage with other brokers?
Are there some factors that the user can make to reduce slippage?
Which are the brokers that have less slippage?
Every broker have different slippage
Why Slippage comes:
Every broker is connected with different LP (Liquidity Providers) , lets say a broker is connected with 5 banks and there different prices offers from banks and Trader looking Trade at 1.50000 price but banks offers different 1.50009, 1..50011 etc but not available at 1.50000 so your Trade will be filled at 1.50009 a close offer from your price so there a slippage , Slippage can come opening trade , at closing trade that's why in news or in fast trading slippage goes wide. If a broker have more LP its possible you will see less slippage, that's why on EURUSD pair always less slippage reason more offers on this pair as most common trading pair.
Slippage can be negative and positive both sides. I explained Straight Through Processing (STP)/Electronic Communications Networks (ECNs) condition.
Low latency can reduce 20% slippage but not much because two prices difference is a fact.
Hope now your clear ,