Forgetting Intention
Question

                I forget to form the intention when doing most deeds.

What should I do?
Praise be to Allah.
    Intention (niyyah) is an important matter, 
    as it is the spirit of deeds through which deeds become valid, as the 
    Prophet (peace and blessings of Allah be upon him) said: “Actions are but by 
    intentions and each person will have but that which he intended.” Narrated 
    by al-Bukhari (1) and Muslim (1907). 

    The intention turns permissible deeds into 
    acts of worship, hence we should pay attention to it and make it for the 
    sake of Allah, free from any element of showing off. 

    It should be noted that intentions are of 
    two types: 

    1 – Obligatory intention, without which an 
    act of worship is not valid, such as the intention in doing wudu, praying, 
    paying zakah (obligatory alms), fasting and doing Hajj (Pilgrimge). This 
    intention is something that no one can do without. If a person does wudu to 
    pray, touch the Mus-haf (written copy of Quran) or in order to be (ritually) 
    pure (tahir), he has formed the intention. Intending to pray or intending to 
    remove impurity is forming the intention when doing wudu. 

    When a man stands to pray, knowing that this 
    is Zuhr (afternoon) prayer, for example, and he intends to offer the prayer 
    and gets up to do it it, then he has formed the intention. It is not 
    essential – and in fact it is not prescribed – to say out loud, “I intend to 
    pray Zuhr prayer” etc., as some people do. This was not narrated from the 
    Prophet (peace and blessings of Allah be upon him), and the place for the 
    intention is in the heart. 

    Similarly, if a person decides at night that 
    he will fast on the following day, then he has formed the intention of 
    fasting. In fact, his eating sahoor (pre-dawn meal)shows that he is 
    intending to fast. 

    It is difficult for a person to forget to 
    form the intention in such cases. 

    2 – The second type of intention is that 
    which is mustahabb (preferable) in order to attain reward. This is what some 
    people forget, which is to keep the intention in mind when doing permissible 
    things, so that they will be acts of worship, such as eating, drinking and 
    sleeping with the intention of strengthening oneself to do acts of worship, 
    as the Prophet (peace and blessings of Allah be upon him) said: “You will 
    never spend anything that you spend for the sake of Allah, but you will be 
    rewarded for it, even the morsel of food that you put in your wife’s mouth.” 
    Narrated by al-Bukhari (56). 

    Mu’adh (may Allah be pleased with him) said: 
    I sleep and I get up (to pray at night), and I seek reward for my sleep as I 
    seek reward for my getting up. Narrated by al-Bukhari (4088). 

    He (may Allah be pleased with him) sought 
    reward for his sleep just as he sought reward for his getting up to pray at 
    night, because he intended by sleeping to gain strength to do acts of 
    worship. 

    Al-Hafiz Ibn Hajar said in al-Fath: 
    What this means is that he sought reward by resting just as he sought reward 
    by striving, because if the intention in resting is to enable one to do acts 
    of worship, one attains reward. End quote. 

    What helps to keep this intention in mind is 
    deliberating, thinking and not being hasty. So you should think about what 
    you are intending to do, take stock of yourself before acting, think about 
    whether it is halal or haram (permissible or impermissible), then look at 
    your intention: what do you want from this? Every time you take stock of 
    yourself and think before acting, this will remind you about forming the 
    intention, until it becomes second nature and a habit that you adopt, so 
    that you will not enter or exit, eat or drink, give or withhold, without 
    having an intention in doing so; thus most of your time will become times of 
    worship. 

    We ask Allah to help us and you to do this. 

    And Allah knows best.