How would one favor the formation of p-TsCl over o-TsCl in the chlorosuflonation of toluene?
Chlorosulphonation using $\ce{ClSO3H}$ is an irreversible, electrophilic aromatic substitution reaction.
In the book Chlorosulfonic Acid, On taking Toluene as the aromatic substrate, it is seen to yield two products -

$para$-tosylchloride i.e. the thermodynamic product (because it is devoid of the steric hindrance offered by the methyl group)

$ortho$-tosylchloride i.e. the kinetic product (because of more activated ortho position due to proximity with methyl $(+I)$ group, which is favourable for the electrophile to attack on despite facing steric hindrance)


At low temperatures like $0-5°C$, the kinetic product is favoured and thus the ortho-isomer is formed. This reaction is exploited in the manufacture of the non-fattening sweetener $Saccharin$.
At higher temperatures like $75-80°C$, the thermodynamic product is favoured i.e. the para-isomer.
According to Chlorosulfonic Acid, The yield of para-tosyl chloride can be increased by 

heating, or

addition of ammonium chloride or other catalysts


However, Clayden instead goes on to suggest on Pages 486 and 566, that the preference of ortho-isomer in chlorosulphonation and para-isomer in sulphonation is due to the fact that the latter is reversible unlike the former.

If the reaction is irreversible (as in chlorosulphonation), the alpha-product is usually formed. (with respect to naphthalene, here analogous to ortho position on toluene)
Sulphonation at low temperatures give the alpha-product by kinetic control and sulphonation at high temperatures gives the beta-product (corresponding to para-position on toluene) by thermodynamic control. The beta product is formed more slowly but it is more stable as there is less steric hindrance.... (as the case in toluene)

...which suggests that chlorosulphonation may not be temperature-dependent at all and shall always yield the ortho-isomer, which I am a bit doubtful about. (help needed)
However, the thermodynamic-kinetic explanation seems very satisfactory to me.